new option: in-research aliens take containment
add new string to language_id.html
add Polish translation; thx radius75!
Merge remote-tracking branch 'upstream/master' into alien-research-in-containment
combine both alien containment options into one

combine alienContainmentHasUpperLimit and alienResearchUsesContainment into one alienContainmentLimitEnforced option
Merge remote-tracking branch 'upstream/master' into alien-research-in-containment

Conflicts:
	src/Basescape/ResearchInfoState.cpp
simplify item removal/restoration logic
fix boolean logic and some grammar
fix typo in lang files
Merge pull request #556 from myk002/alien-research-in-containment

addition to containment limits option: in-research aliens take containment