Squashed commit of the following:

commit 852aac122bcface04e3b55062b303e7d6cd7f6b0
Author: Anth Richardson <anthrblahblah@gmail.com>
Date:   Wed May 15 23:26:15 2013 +0100

    - Implemented the SteeringManager object, and IMoveManageable interface for entities to plug into to have their movement handled.

    - Implemented the DrawPrimitives static class, to draw lines and dots.