Robust, well-tested Value Change Dump (VCD) Parser

From: https://github.com/filmil/go-vcd-parser Value Change Dump (VCD) File parser This is a parser for the Value Change Dump files, a.k.a VCD file format. The file format is defined in the IEEE Standard 1800-2003. Specifically, the format supported at the moment is the 4-value format. Some pragmatic extensions are supported, such as those produced by the nvc VHDL simulator. The correct behavior of…