Fixed #102 + Fixed some small memleaks

Fixed a bug that caused app to crash sometimes when leaving/stopping the level/program.
The reason for this problem was that there could be some tasks in several queues that could be scheduled e.g. after the ScenePresenterViewController is dealloced.
Especially those runNextAction jobs that uses formulas and want to read position values/coords from the sensor handler caused the crash, because they wanted to convert the given scenecoordinate of the SpriteObject to a point via the Scene. But the scene is not available at this time any more -> memory access violation.
[((Scene*)self.scene) convertSceneCoordinateToPoint:super.position];
For further details please read Marc's description for issue #102.

Marc also solved some analysis bugs displayed by the XcodeServer.