Fix invalidateOrder call; added OneShotEf to the model
Several improvements
Merge branch 'master' into scene2d

Conflicts:
	core/engine-core/src/main/java/ead/engine/core/gameobjects/sceneelements/SceneElementGOImpl.java
	core/engine-core/src/main/java/ead/engine/core/gameobjects/sceneelements/SceneGO.java
	core/engine-core/src/main/java/ead/engine/core/gameobjects/sceneelements/transitions/DisplaceTransitionGO.java
	core/engine-core/src/main/java/ead/engine/core/gameobjects/sceneelements/transitions/FadeInTransitionGO.java