Add death by wall collision functionality.

	*Death by snake collision still to go.
	*unsetting the interval loop turned out to be
	really easy.
	*Somewhere along the way, the xCoord and yCoord for
	food have gotten funky
Fix snake backwards moving error

	*Snake now moves and dies correctly
	*case statements are a little crazy but I'm ready to move on.
	*next up: instituting shiny-nosity and prettifyittude
Remove uncessessary console logs and comments
Merge pull request #3 from mathildemouw/snake_death_observer

Snake death observer