vle-1.2.0
vle: switch to vle-1.3
gvle: switch from Gtkmm2 to Gtkmm3
Fixes for gtkmm3:

- remove unused mEditActionGroup in ConditionBox.hpp
- fix makeMenu of ConditionBox.cpp
- add dependency on cairomm (still needed)
- update gvle.pc file for compilation of extensions