Add Animation implementation.

* a new action function Animate, animates Entities
* additional method on EntityPool, to get Entities by ID
Transfer of old InputSystem for reference.
Add the first draft of the input subsystem, and extra fixes.

* Rename InputSystem to Engine (referenced as Input::Engine via the Input namespace)
* Add Event class, which holds a union of smaller data structures for input events
* Renamed a Clock method from FrameStep to AdvanceTime
* Add a Simple Input Handler (SIH) in action functions
* Add references to the Input::Engine in ServiceLocator
* Rename LuaEngine to Engine (referenced as Script::Engine via the Script namespace)
* Change KeyCodes slightly to adhere to new location and change in the whole framework
* AbstractWindow class gained an event queue list pointer