Implemented Boss Level fully. Other small fixes.

- Added Level 4
- Implemented variable levelID to change levels ( 4 max currently)
- Added checks in Load level to not try to create Boss, Flag, or castles
if they dont exist (was causing an error)
- Implemented more checks in the Question Box but still not working
totally. Sometimes its possible to hit a Question box on the side, and
the coins is triggered. Still needs a little more work.