Bug Fix V - The Bulletproof Fix

-Shields can no longer stack. This can accommodate an extra points
feature for obtaining extra shields.
-Bullets have gravity disabled and are tagged as Bullets.
-There is a set limit on how many bullets are allowed on the playing
field. This is to avoid unecessary spam.
-Bullets will destroy themselves when they are out of the camera view.
Correctly implemented mute option

-Mute will suppress both SFX and music in game.
-Button sounds are affected as well.
No more offscreen time for Mathius

This commit fixes Issue #2.

Mathius will no longer appear offscreen.

Other fixes:
-Removed Graphics for the original numbers as they are no longer used.
Merge remote-tracking branch 'origin/Bug-Fixathon' into Release-Builds