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.
Move path preview removal from inventory state to inventory button

because seems a neater place for it.
Fix inventory button in debug mode not always resetting TUs

Currently you need a unit with an inventory screen to reset TUs.  A lot
of aliens do not have an inventory screen so if there is no convenient
alien around you are stuck.
Fix displaying stats for wrong unit during debug turn.

Updates stats while watching aliens move; currently seeing stats
for the previous alien.
Also when you get to play aliens ensure that the stats for the
currently selected alien are shown; again previously moved alien
stats are displayed.
Fix broken string
Merge pull request #773 from cfailde/string

Fix broken string
account for carried comrades at debriefing.

turns out i forgot to include this in debriefing, having only applied it to
units actually reviving from unconsciousness.
sanity check for good luck.
no reaction fire with unresearched weapons.
battleAutoEnd... we meet again.
save motion points.
fix unit turning
Remember that we complained.
keep track of income and expenditure more closely