added EventPhase and additional base members as used in lostengine/guiro
moved EventHandler typedef to "lost" namespace
removed Frame member since not needed right now, added containsPoint for event handling
added methods for visibility handling and containsPoint, that use the underlying Layer instead of redundant information as in lostengine/guiro, removed inheritance from EventDispatcher since three dispatchers are required for the different phases
started to port lostengine/guiro/EventManager