ticket:10098: Fixed LCID to posix-style locale ID mapping problem. The fix required to change the internal LCID mapping function interface, and resolved a threading issue in uloc_getLocaleForLCID() and some other internal implementation problems in Win32DateFormat/Win32NumberFormat.

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk/source@33586 251d0590-4201-4cf1-90de-194747b24ca1