Improve type error messages for variable assignments
Simplify FlattenCompoundTypes
Clean up InlineNodeCalls
More code clean up
Merge branch 'master' into function

Conflicts:
	jkind/src/jkind/analysis/TypeChecker.java
	jkind/src/jkind/translation/FlattenCompoundTypes.java
	jkind/src/jkind/translation/InlineNodeCalls.java