Build wxWidgets port by default
Enable link functionality by default
Moved the GTK portion of CMakeLists.txt to its own file
Cleaned up and updated .gitignore files
Make sure GTK build is accessible at top level directory.

This is what the wxWidgets build does.
Ignore any games used for testing
Removed an unneeded include from wx cmake file

It's part of libvbamcore already
Cmake now gets version information from git