More type-checking on functions.
Merge branch 'master' of https://github.com/metaborg/metac

Conflicts:
	BaseC/trans/typing/constraints.str
	BaseC/trans/typing/types.str
Resync after branch merge
Merge branch 'master' of https://github.com/metaborg/metac

Conflicts:
	BaseC/trans/naming/names.str
	Statemachine/trans/statemachine-names.str