custom cursor

Added custom cursor texture and script to change cursor.
Merge pull request #1 from justin1121/JustinDev

custom cursor
Merge pull request #2 from itsbriany/JustinDev

Justin dev
Added a gun script with shooting and a base file that handles getting hit by a bullet (for the zombies)
Removing crosshair.cs, no longer needed
Updated some message between scripts. Added scripts to track health, energy and score (very abstract)
slight changes to health and energy files plus added GameManager.cs for handling level changes, gui changes, player death, and game start
Merge pull request #3 from itsbriany/JustinDev

Justin dev
Merge branch 'JordanDev'
Merge branch 'master' of https://github.com/itsbriany/GameDesignProject
Merge branch 'master' into JordanDev