bWorldPanning flag. Also added some NULL pointer checks to the
hires texture loading code.
- Added Sector_SetFloorScale2 and Sector_SetCeilingScale2 line specials.
They are mostly the same as Sector_Set*Scale but take fixed point parameters.
This makes them easier to use and more precise than the old ones which
offered very small fractional precision.
- Changed Thing_Deactivate so that passing a tid of 0 deactivates the calling
actor.
- Added MeansOfDeath parameter to DamageThing.
SVN r350 (trunk)