Added transition function that enables the changing of maps. Also added a lot of TODOs that will be implemented later because it's 2am.

Furthermore I'm an idiot and accidentally discarded my BattleSystem
class when syncing so I'll redo that later.

Notes:
+Transition function is in the world class.
+Call to the transition function is in the player class.
+Everything is currently hard coded to make sure functionality works.
Once we get collisions properly working is when I'll change it so it's
more generalized/data driven since I need textures/data.
+ Still trying to get the camera working but I'll work on that later --
still getting used to the different positions the player has and how
that would translate to the world. Think I might use tile based system
instead of using the game window screen once boundaries get set up.