Note: These tests are failing because the pack and unpack functions in
Data.ByteString.Char8 are for ASCII *only*. QuickCheck is easily finding
Unicode strings that don't convert correctly using this method. This
will be addressed in another commit.
Also added dist-* to .gitignore for more modern cabal build artifacts.

If anything but ASCII or ISO-8859-1 is being worked with, it's safer to
convert between String and ByteString through Text's encodeUtf8 and
decodeUtf8 functions. The pack functions in Char8 are for ASCII only.
This may bite people more than they think, say with UTF-8, which is VERY
common.
This fixes the broken property tests added in an earlier commit.