Add images to view

Integrated images into game. The images themselves need some refinement--look a little jaggy.
* changed image names to be like 'black-[whatever piece]' removing the heinous mispelled 'peice' ;^)
* added image column to Pieces model
* modified initialize_the_board! on the Game model to include the new image attribute (term?)
* modified the game/show view  to replace text attribute placeholders with images (spacing also needs tweaking)