small refactor

no need to pass race as an argument, as it may get changed and re-cast after
entering the function.
cancel abortion between stages

wait... what?
Merge branch 'master' of https://github.com/SupSuper/OpenXcom into oXc_kL

Conflicts:
	src/Battlescape/BattlescapeGenerator.cpp
	src/Battlescape/BattlescapeGenerator.h