smooth collisions
Merge branch 'Gameplay-Collision' into Gameplay
Merged Clarks Movement with Joshs collisions.
Added headers to code.
Commented out acceleration system.
Collisions are smooth.
Modified some components.
Loaded up test walls and obstacles in the main.cpp.

Conflicts:
	src/Gameplay/collision.h
	src/Gameplay/collision_system.cpp
	src/Gameplay/main.cpp
	src/Gameplay/movement_system.cpp
	src/Gameplay/world.cpp
	src/Gameplay/world.h
Added proper smoothed movement for the player.

Smoothed and fluid movement added for players, there is momentum and
acceleration during motion.

Things than need fixing: The player accelerates/deccelerates %141
faster when moving in two axis rather than 1 (eg, up and right).

The top speed of the player is constant in any direction.
Merge branch 'Gameplay' into Gameplay-Collision