ticket:10253 Plural Rules, work in progress.

git-svn-id: http://source.icu-project.org/repos/icu/icu@33940 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10255: set flag even on =1 case, add documentation

git-svn-id: http://source.icu-project.org/repos/icu/icu@33941 251d0590-4201-4cf1-90de-194747b24ca1
ticket:9101: fix reset twice before root CE; adjust special reset positions according to previous rules

git-svn-id: http://source.icu-project.org/repos/icu/icu@33942 251d0590-4201-4cf1-90de-194747b24ca1