Optimized, distinguished board-ready code, improved comments

- placeFood() was significantly optimized.
- Clarity of comments and some code were improved.
- The endGame() snake-collapsing visualization was lost to make the translation from this test build to the final build easier (the visualization will show up as intended with display functions operating in another thread).
- Functions are now split into game-agnostic functions (many of which require lodev support), test functions (to be removed in final versions), and board-ready functions.
-Additional details for this version are located at the top of the code.