ticket:10553: Implement context-sensitive capitalization for relative dates (C), add en contextTransforms for test

git-svn-id: http://source.icu-project.org/repos/icu/icu@34718 251d0590-4201-4cf1-90de-194747b24ca1
ticket:9101: add contraction flag for when there is no match for the single code point, which fixes some prefix+contraction matching and mapping enumeration; broaden a contraction fastpath beyond Latin

git-svn-id: http://source.icu-project.org/repos/icu/icu@34719 251d0590-4201-4cf1-90de-194747b24ca1