Minor bug fixes, feature additions and changes.
- Added settings menu to the pause menu.
- Fixed jittery movement of PB UI when moving.
- Ability to remove HUD with 'F1'.
- Added ability to go to next map by pressing the space key (if next map is unlocked).
- Added ability to go to previous map by pressing the left control key.
- Increased slightly the height of the lower hallway in map '1-15'.
- Changed lighting in all maps in Campaign 2 ( Xayzavian ).
