ticket:10128: add 2 new script codes from ISO 15924: Aghb & Mahj; adjust cintltst code for new Bidi_Class values and some other changes

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/markus@33564 251d0590-4201-4cf1-90de-194747b24ca1