Initial gtk3 porting, still a lot of bugs!
More fix on Gtk3
Fix credit page formating.
Fix main window glade file.
Remove deprecated gtk_vbox/hbox call
More deprecated stock icon fix.
Some UI fixes.
UI tweaks
Fix compilation preference.
Reformat all code with tab stop 2
Fix most of warning.
Fix synctex_parser warnings.
Fix more warning.
Fix deprecated widgets in ui files.
Add README.md