Update - Gameplay and Bug Fix

First update is here to improve upon the gameplay and fix a bug I discovered.

1. The Player is now able to run. The player has regenerating stamina and is able to run using the left and right shift keys. Stamina is indicated by the bar on the bottom right underneath the ammo counter.
2. The killer now has faster walk and run speeds. This should increase the difficulty of the game by making sure the player must run or shoot the killer to escape.
3. Players can now hear the footsteps of the killer if he is close enough.
4. Fixed a bug where the "Restart Level" button didn't work.