Selection object, to control different contexts and selections
SelectionCommand and SelectionEvent relies in new selection object
Added selection object to model
Selection test
Updates after API change
Updates tests after API change
SceneView uses selection contexts
pushContext->pushStack, to avoid confusion with the term "context"
Clipboard uses context. Cut test updated
Fix after rebase
Updated Tracker
Added basic implementation for Google Analytics tracker
API updated
MoveByEntity component. Just updates the entity's position according to the speed of a target
Parallax. A special case of MoveByEntity that updates an entity's position in opposed direction to current camera's speed
ChaseEntity component. Tries to keep the entity within max-min distance from target.
To do: take PathBoundary into account, if present.
Little refactoring in Velocity Component
Simple test
Comments addressed + 1 minor fix in MoveByEntityComponent
Comments addressed.