Log Message:
Update to 2.2.0:

Changes since 2.1.10:

* Several stability fixes, found with Valgrind and the Fedora retrace
  server
* Use GTK+ 3 by default, but still allow building against GTK+ 2
* Support extended tag fields in MP4 files
* Support GIF images in tags
* Abhinav Jangda’s Ogg Opus support, asynchronous image loading, scanner
  function tests and new Vorbis cover art support
* Santtu Lakkala’s MP4 cover art and GIO support, fix for Roman numeral
  capitalization
* Ask for confirmation before overwriting during renaming
* Ekaterina Gerasimova’s Mallard help updates
* Avoid truncating Vorbis audio data when saving
* Gianvito Cavasoli’s Italian translation update
* Alexandre Franke’s French translation updates and typo fix
* Wolfgang Stöggl’s German translation updates
* Piotr Drąg’s Polish translation updates
* Мирослав Николић’s Serbian \ 
translation update
* Daniel Mustieles’ Spanish translation updates
* Balázs Úr and Attila Hammer’s Hungarian translation updates
* Enrico Nicoletto and Rafael Ferrera’s Brazilian Portuguese translation
  updates
* Marek Černocký’s Czech translation updates
* Aurimas Černius’s Lithuanian translation update