Fix #117: Implement java.lang.Character.digit
Fix #109: Handle LabelDef for while (false) {}
Fix #104: Correct hash for boxed Byte, Short and Int
Fix #116: Correct comparison for boxed Float and Double
Fix #113: Prepend a Char to String
Implement java.lang.Character.isWhitespace
Merge pull request #120 from gzm0/bugfixes

Various bugfixes