ticket:10128: add support for UBA 6.3 BPA (Bidi Parenthesis Algorithm)

git-svn-id: http://source.icu-project.org/repos/icu/icu@33874 251d0590-4201-4cf1-90de-194747b24ca1
ticket:9101: move CE buffer from CollationCompare into CollationIterator, fewer copies of CEs, simpler

git-svn-id: http://source.icu-project.org/repos/icu/icu@33875 251d0590-4201-4cf1-90de-194747b24ca1