fix projectile drawing based on direction
better names for vars

because upper may be lower than lower
Fix ethereal walking sound
Fix No Psionics mod not affecting aliens
fix unit sprite location while meleeing
initialize Screen::_flags (avoid UMR)
Merge pull request #866 from ajschult/umrBranch

initialize Screen::_flags (avoid UMR)
make all the air above the landing craft visible.
initialize BattlescapeState::_reserve to avoid UMR
Merge pull request #867 from ajschult/umrBranch

initialize BattlescapeState::_reserve to avoid UMR