Added a few example sprites from a Roguelike Tileset [see: http://opengameart.org/content/roguelike-tiles-large-collection].

Added texturepacking and very simple basic of textures.
Added Map, Grid and GridCell classes to handle
the model portion of the game.

Added InputMultiplexing and initial code to detect
which object in the model was touched by the user.
Currently only works for detecting which Cell was
clicked.