ticket:7912 C wrapper for Formattable - UFormattable


git-svn-id: http://source.icu-project.org/repos/icu/icu@33849 251d0590-4201-4cf1-90de-194747b24ca1
ticket:9101: better encoding of specials: impossible case bits as marker, not FF primary byte

git-svn-id: http://source.icu-project.org/repos/icu/icu@33850 251d0590-4201-4cf1-90de-194747b24ca1