Some progress made

-The player can still jump and fall and walk on platforms as before,
however there is the ground work for side collisions in place.
- I discovered a few flaws in logic, stepping back to re-evaluate.
- I must reconsider how the onGround flag is set, so it isn't un-set
while checking all other platform collisions.
- Right now, it seems to only deal with collisions for one platform at a
time. Only when the player jumps is player set to the position for side
collision.