- An error during the upload now no longer hangs everything (GUI changes placed
   in main thread)
 - Some formatting changes
 - Update version in manifest (I think a new minor version is in order for GTK3
   support!)
 - Add self to authors in manifest (shameless plugs, whoop whoop)
 - Remove claim of supporting older versions of gajim

 - Move thumbnailing code into separate module
 - Port GdkPixbuf thumbnailer to gtk3
 - Make GdkPixbuf thumbnailer more efficient
 - Better exception logging
 - Some code reformatting

Not perfect yet, some layout issues remain, but it works.