TESTS: For integer!, add positive?/negative?,max/min,odd?/even?,complement
and power tests

TESTS: For logic!, add complement tests.
TESTS: For block!, add max/min tests.
TESTS: For char!, add max/min, odd?/even? tests.
FEAT: Enable POWER action! in boot.red
FEAT: BLOCK! comparasion now compare elements's datetypes when their types
are not the same.
FEAT: minor refactor for decode-utf8-hex in string.reds
FIX: Wrong result when compare empty string! and block!
Merge pull request #777 from qtxie/add-tests-1

TESTS: For integer!, add positive?/negative?,max/min,odd?/even?,compleme...