Make compilation work with newer (actually all) libxml++ and bump C++ mninimum version to 17.

Bug fix:

• Clipboard: Fix compilation failure

New Features:

• Add Append action to add subtitles from another files with their timecodes as-is.
• Add keyframe command line switch and automatically open keyframes (and open keyframes automatically when they share filename with other files)
• Implement BorderStyle=4 for ASS subtitles (libass only) to show rectangular box even for two- and more-line subtitles.
• Add AutoWrap action that wraps subtitles into lines that are shorter than Maximum Characters per Line

User Interface Improvements:

• Make mpv show window when playing audio files
• Sort keyboard shortcuts alphabetically and show dynamic ones first
• Add modern format like MP4 to autoopen
• Simplify Move plugin: use current position as new time, provide better feedback on nonsensical user input and by default move all subsequent subtitles when only one subtitle is selected
• Changing playback speed now does not distort sound (pitch)
• Join Subtitles now by default offsets the new subtitles by the length of the video, but the offset can also be set by the user
• When creating a new file from clipboard or when importing from plaintext, add an extension
• Use em-dash instead of a hyphen in user facing strings
• Force ratio option is now better explained
• For empty files, set format based on extension (so opening empty file.srt no longer throws an error)
• Use radio buttons to indicate which view is active and also make changes to a view apply immediately.
• GUI: Make lines longer than max char per line bold and red
• GUI: make it impossible to select uneditable columns (like subtitle number)
• Fix labels and tooltip displayed at the bottom of the window when hovering over menu items: now all should have a tooltip, and often with more precise wording
• Import and export are now in File menu, not its submenu (they were only items in the submenu previously)
• Add shortcuts, icons and change order of Clipboard actions

Bug fixes:

• Clipboard actions in the menus are now properly faded when not applicable
• Respect layers when reading an ASS file
• Style editor no longer shows default style twice
• Make styles editable for new files
• Remove leading zeroes for margins when reading ASS files (so now margin is 0 and not 0000)
• Handle Unicode BOM properly
• Fix crash on mouse move and click in empty waveform renderer with unsaved non-empty file
• Stop emitting GTK warnings when using the clipboard plugin
• Fix typoes

Development & Modernization:

• Change default clang formatting and save all files with it, hopefulyl making the style more uniform
• Moved from gstreamermm to gstreamer C API, which should make playback a lot more reliable and improbe Wayland support (thanks Kitone!)
• Improve .gitignore
• Add info on how to make a release to README
• Remove some obsolete content
• Fix compilation warnings for ASS subtitles plugin
• Make Style editor work when running local build
• Make ti possible to compile with libxml++3.0
• Sort all accessible bugs from GNA! and either fix them or open new issues on GitHub

The last time was seven years ago, hope to not screw up the release :)

The repository moved from http://github.com/kitone/subtitleeditor to http://github.com/subtitleeditor/subtitleeditor

• New Features:

  • Add option to sync subtitle selection with player position. Patch by Tomáš Hnyk
  • New "Find by Time" plugin to find subtitle at current video player position. Patch by Tomas Partl
  • New "Select Clipboard Overlap" command to select subtitles that overlap timewise with clipboard. Patch by Tomas Partl
  • New "Paste Over Time" command that overwrites subtitle timing from clipboard. Patch by Tomas Partl
  • New "Paste Unchanged" command that pastes subtitles without changing their time codes. Patch by Tomas Partl
  • New "Idealize Duration" and "Idealize Duration From End" commands. Patch by Tomas Partl
  • New "Slide Words" plugin to slide words between lines and between subtitles. Patch by Tomas Partl
  • New "Slide Timings" action plugin. Patch by Tomas Partl
  • New "Select to End" command. Patch by Tomas Partl
  • Add preference for Ideal Characters Per Second on the Timing page. Patch by Tomas Partl
  • Add option to make jumping to subtitle by typing its number optional. Patch by Tomas Partl
  • Grouped paste methods into new "Paste Special" submenu. Patch by Tomas Partl

• User Interface Improvements:

  • Show both audio and video in Open video dialog by default. Patch by Tomáš Hnyk
  • Video player and waveform are visible by default to reduce user confusion. Patch by Tomas Partl
  • Replace mplayer with mpv as default external video player with better defaults. Patch by Tomáš Hnyk
  • Move "Select Clipboard Overlap" to Selection menu. Patch by Tomáš Hnyk
  • Added flash messages to various commands for better user feedback. Patch by Tomas Partl
  • Add higher size icons. Patch by Tomáš Hnyk
  • Improved "Set Subtitle Start from Player" to move whole selection of subtitles. Patch by Tomas Partl

• Bug Fixes:

  • Don't save empty entries to recent files list. Patch by Tomáš Hnyk
  • Get text for replacement before replacing, not after find. Patch by Tomáš Hnyk
  • Make Dialoguize and split subtitle also apply to translation. Patch by Tomáš Hnyk
  • Make Find by Time and Select With Player include the endpoint. Patch by Tomáš Hnyk
  • Make find by time find the closest subtitle when player position is between subtitles. Patch by Tomáš Hnyk
  • Fixed bug in error checking where max chars per line checker would hang. Patch by Tomas Partl
  • Fixed bug in slide words action where sliding last word would affect other lines. Patch by Tomas Partl
  • Fixed slide timings plugin to prevent subtitles from being shifted out of bounds. Patch by Tomas Partl
  • Fixed bestfit plugin to respect minimum subtitle duration. Patch by Tomas Partl
  • Fixed infinity loop on generate_untitled_name
  • Fixed compilation with --disable-nls. Patch by Gilles Dartiguelongue
  • Fix #13: Compiling - enchant dependency not met when enchant-2 is installed
  • Fixed build with old version of enchant. Patch by Nikolay Shaplov
  • Fixed Wayland support in OpenGL video output. Patch by Jakub Adam
  • Hide video overlay when player gets unmapped. Patch by Jakub Adam
  • Don't allow shrinking the multimedia pane. Patch by Jakub Adam
  • Fixed bug. Patch by yzrsng

• Development & Modernization:

  • Target C++14
  • Modernize code: use nullptr instead of NULL, default member initialization
  • Use range-based for loops throughout codebase
  • Use auto keyword for better code clarity
  • Reformatted source files using clang-format
  • Added .clang-format file for consistent formatting
  • Reworked config API
  • Refactored se::documents API around DocumentSystem
  • Renamed se_debug* functions to se_dbg*
  • Single-parameter constructors marked explicit
  • Cleanup: removed obsolete files, improved comments and licensing

• Translation & Internationalization:

  • Add Basque translation. Patch by alexgabi
  • Update translation files for missing strings. Patch by Tomáš Hnyk

• Build System & Packaging:

  • Update appstream metadata to current format. Patch by Philip Rinn
  • Move appstream metadata to new location. Patch by Philip Rinn
  • Use new format for application id. Patch by Philip Rinn
  • Stop installing SVG app icon in pixmaps directory. Patch by Pino Toscano
  • Fix metadata license in appdata.xml. Patch by Balló György
  • Make build reproducible. Patch by Philip Rinn
  • Don't use absolute path for actionplugindevdir variable. Patch by Philip Rinn

• move from gna! to github
• Replace std::auto_ptr with std::unique_ptr.
• Merge pull request #4 from innir/remove-gna-links
• Fix sr #3373: Compiling subtitleeditor-0.52.1 '--disable-nls' fails with '/usr/include/libintl.h' errors : (Peter Levine )
• Fix some spelling errors. (Philip Rinn )
• Fix: setup the default value of do-auto-timing-check in the timing group.
• Fix constructor order
• Fix constructor order and formatting
• Fix bug #25243 : Fix some spelling errors. (Philip Rinn )
• Fix bug #25184 : Fix build with gstreamermm-1.0 1.8.0. (Philip Rinn )
• Fix bug #24949 : Remove deprecated gnome-common variable GNOME2_DIR.
• Fix: Ask for maximize-window instead of window-maximized config key.
• Fix appdata screenshoot
• compile with Wformat-security
• Change homepage links to github (Philip Rinn)
• Change domain of email address to 'free dot fr' (Philip Rinn)
• Build with the flags -Werror=reorder -Werror=float-conversion.

• Fix bug #24407 : Undo/redo should be unlimited/have configurable limit/ higher limit
• Fix bug #24066 : Trailing spaces count for cps calculation.
• Fix bug #19010 : subtitleeditor needs a style template system for all formats.
• Fix bug #23714 : glibmm 2.45.40 requires C++11 -- please build with C++11 support
• Fix bug #23714 : include memory and build string using compose.
• Fix bug #23714 : Explicit cast. patch by Philip Rinn
• Fix bug #24302 : FPS Field in change Framerate dialog not editable anymore. Port to gtk3 and fix regression.
• Fix bug #23727 : Error Checking should close on pressing Escape.
• Fix bug #23718 : Move plugin should remember the checkbox to only move selected.
• Fix bug #23706 : Error checking preferences should be the same in preferences and error checking. Patch by Tomáš Hnyk
• Bump dependence of gtkmm from 3.0 to 3.10