yay gravity fixes.
pixel fix for pathfinding thing
fix some broken walls in alien bases and abductors
fix sanity check
ammendments to facility destruct sequence
tidyin
fix typo

thanks to cfailde for pointing this out.
some explosion tweakage

don't start any explosions at a frame above 0, instead, range the starting
frame between 0 and -4 (meaning a 4 frame delay) and layer the explosions
accordingly. distribution should be more or less equal between these frame
delays.
Merge remote-tracking branch 'upstream/master' into WIP
Finally everything compiles with no crashes

Inventory is now running, need many tweaks and corrections, YAML loads
and inventory loads. Geo GUI needs to be color corrected also.
Color corrected inventory and Geo

The Globe GUI has been corrected to use correct palette as well as the
inventory all items are not properly displaying in the proper locations,
small tweaks still needed since larger (high resolution) items get cut
off. due to slot size restriction.
Merge pull request #12 from Xracer/WIP

Merged Upstream into HDOXC