Cheese 3.9.5 Fixes Three Bugs and Updates Translations

Cheese 3.9.5 fixes bug 704119 by removing cheese-actions.ui from po/POTFILES.in and uses GAction for thumbnail pop-up menu actions. This version also refactors the thumbnail context menu event handling by using Gdk.Event.triggers_context_menu() rather than checking if the secondary button was pressed (it will return true if the event was handled, in order to stop further event propagation).