Add the DIRECTIONAL_INPUT event.

Now we have potential for directional input from the keyboard.
Add a responder event to the event listener.

Useful for cases when an event has to return something. Also cuts out half
of the entity specific events requirements.
Merge branch 'behaviouralcorrection' of github.com:dreac0nic/nimbus into behaviouralcorrection
Revert "Add the DIRECTIONAL_INPUT event."

This reverts commit f84205f9b1234addc037a991cb095f567d0f5f58.