UI fixes
enforce unit selection for camera centering on load
fix multiple MC scenario

if we run out of _knownEnemies, psiAction() won't fire, and the _psiAction
won't get reset, resulting in aliens attempting to MC empty tiles
Merge branch 'master' of https://github.com/SupSuper/OpenXcom.git into main_line
fix operand in fallState
fix mistake in die state re: exposure

shouldn't really matter, but safe > sorry
fix certain damage types passing through walls

most noticably stun damage, but also incendiary and smoke.
fix ctrl+alt+kill function
Merge branch 'master' of https://github.com/SupSuper/OpenXcom.git into main_line
/Zm150
make tank/cannon article consistent with other HWPs
Merge branch 'master' of https://github.com/SupSuper/OpenXcom.git into main_line
game doesn't end when missions run out.

had to remove references in favour of making copies, because reasons.
prioritize better weapons for auto-equip

reverse that iterator!
Avoid conflict: src/Geoscape/GeoscapeState.cpp
Merge branch 'number_of_missions' into main_line