Machine Gun Sprite Added | Bugs Fixed

1. Machine gun unlock now gives the player a new gun sprite to represent the new gun.
2. Text changed to represent that the unlock is indeed a machine gun, as well as upgrading the extended clip to x5 ammo instead of x3.
3. FPS counter added.
4. 300 FPS max limit added. (This will stop the game from stressing out your computer a little.)
5. Fixed a bug where player kept shooting while game was paused in the shop.
6. Working on a system to add more guns as well as swap between weapon unlocks!