[DF-1346] Added new commands to manipulate scene structure
[DF-1346] Added new scene system to edit scene structure.
Small fixes
[DF-1346] New structure system included into sceneeditor2
Added new moveTo functionality into camerasystem
Fixed wrong landscape bounding box in collision system.
Added undo/redo operations for sceneEditor2
[DF-1346] SceneTree now handles remove entity command.
Merge branch 'development' of https://github.com/dava/dava.framework into development