Update to gtk-mac-integration 2.0 API

Fixes bgo#687766. quartz_application_... becomes
gtkosx_application_...

https://bugzilla.gnome.org/show_bug.cgi?id=687766
Updated Basque language
Do not use X11 color names
Removed X11 color names.
Add unit tests for the UndoManager

There is one bug. To easily locate it, it is inside #if/#endif.