Added javadoc comments for Player.java

Added javadoc comments for Player.java
Added javadoc to Platform.java

Added javadoc to Platform.java
Added class RunningState.

RunningState sets up the user inputs associated with running and
jumping. It is mostly a proof of concept for what we could do with
AppStates but it could be useful if we would like to have a power up
that makes the Player fly etc.
Minor fix
Deleted the deprecated SceneObjectDataSource classes.

Deleted:
PlayerSceneObjectDataSource.java and
SceneObjectDataSource.java.
Added debug messages for "jump" input.

Added messages when the jump mapping is triggered.
Activates user input in the RunningState rather than in the InGameState

Removed old user input initialization and replaced it with the
attaching of the RunningState. The inputInitializer still adds a
Listener to the "jump mapping".
Minor fix