Fix compilation against new GTK

API changed a little bit in latest GTK in openSUSE Factory, made few
adjustments (mainly get_font functions) to make package build again.
Merge pull request #22 from miska/master

GTK compilation fix
GTK compilation fix
Backward GTK 3.6 compatibility

Previous commit fixed build against new GTK, but broke build against GTK 3.6.x.
Adding compatibility wrap-up to fix build for older GTK as well.
Merge pull request #23 from miska/master

GTK 3.6.x backward compatibility
- fix for bnc #801311: Translation is missing
- 2.42.5
adapted call for locale dir and theme dir
changelog
increased version
Merge remote-tracking branch 'upstream/master'