It seemed a bit silly to have to require 2.14 just for the about dialog, so for now I bumped it back to 2.12 and disabled the url/email code for gtk+ < 2.14
This can be used to produce a zip file which can be distributed and run without installing. Use ./configure --enable-bundle and after 'make bundle' to produce the bundle.
The lane collapse preference works, search filter not yet. Also, colors for the diff were implemented, but due to a limitation in gtksourceview this does not work (and is not yet committed).