Better typerule for the select operation
Only check types of the expressions in the concept function
Better subtyping replacement for join, cleanup meet
Match any type with a join on adding an equation
Rebuilt closures and collections
Rebuilt typesystem lang
Kill old broken hack
Reflectivity for NullType
Get rid of meet type in final expansion
Fixed tests
Ensure final expansion in single typ calc mode
A runtime type variable is never a subtype of another type
Meet and join types are not structural, must report argument variables as input
MeetType is subtype/comparable of/with (exactly) its args
Fixing inequations processing
Explicitly cast "semantic downcast expr" to ClassifierType
Temporary workaround for typechecker's deficiency
NPE guard, MPS-18336
Merge remote-tracking branch 'origin/3.0/fisakov/typesystem'

Conflicts:
	languages/baseLanguage/baseLanguage/languageModels/typesystem.mps
	plugins/mps-build/languages/build.mps/languageModels/behavior.mps
	plugins/mps-build/languages/build.mps/source_gen/jetbrains/mps/build/mps/behavior/BuildMPSPlugin_Behavior.java
	plugins/mps-build/languages/build/languageModels/behavior.mps
Rebuilt required