Implemented set_date method, moving update of ::date attribute to another call
outside the construction process. The method can be used to set or update the
GcalView::active-date property
Implemented changes from GcalView API
Integrated GcalWeekView into application flow.
Refactoring the code inside GcalMonthView for drawing and for showing child
widgets.
Fixed ref_sink in GcalEditableRemainder. (Don't need it)
Added translation for weekdays abbreviation. (Thxs to ebassi & mclasen)
Passed make distcheck.
Erick Pérez Castellanos