Added I18N strings.
Dummy Picture/Video desktop implementation.
Added Scenes UI widget.
Picture refactorings, added new UI panel.
Behaviours panel improvements.
UI widgets improvements and refactorings.
Now EditionWindow pushes/pops commands contexts.
Avoid copying to project when the resource is already in the project.
Now BrushStrokes pushes/pops commands contexts.
Fixed a bug with a widget while changing title/description of a note.
ProjectScreen no longer displays video/picture buttons.
Small galleries improvements.
Added more options to import an element to a scene in SceneEdition.