Timeline examples

[hoshiryu]

Add two plugins for animating data examples:

• EntityAnimator which allows to animate an Entity by keyframing its tranform
• MeshAnimator which allows to animate a Mesh vertex's position or normal by keyframing it

[MathiasPaulin]

These plugins add too many informations on log system and main-app gui. They also make the main-app to crash at exit and are not really usable.
Will be merged when all problems will be solved.