parameter verification
adjustment of UString to make use of parameter verification
Merge branch 'master' of https://github.com/clever-lang/clever

Conflicts:
	core/value.h
additional of array and boolean to check_args
declare macro clever_check_args in clever.h
rename method
type checking for the current type only
Merge pull request #219 from krakjoe/master

CLEVER_VERIFY_ARGS