Schema
Executor
Test
Added a method in game loop that creates a component for an entity, if not exists, and return it
Making use of recently created method
Merge pull request #623 from jtorrente/createandget

Add and get method added to gameLoop
Merge pull request #622 from jtorrente/repeat

Repeat control structue
Clip engine view
Simplified structure to relate EngineEntity and Actors

Now, instead of each EngineEntity having a group that has a child
which is the renderer, the renderer is directly associated to the
EngineEntity.
Added a default container in group editor

So panning/zoom isn't performed over the scene container directly,
which was provoking some side effects.
Tests fixed after changes
Refactor TouchListener