Changed inner workings of engine #2

Improved overall handling of game objects
Merged rendering to be centralised
Added resource management
Generalised engine to work with any deviation of RenderPanel
Added unchaotic creation and progression of enemies.
Improved input to resemble true movement.

Drawing of (almost) how the engine now works:
![c27d0518-94c9-11e3-99e2-1a8bba596fc3](https://f.cloud.github.com/assets/550237/2171479/85bfec92-9584-11e3-9711-dae948d68529.png)