ticket:10051 Mutexes, fix Windows build problems.

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/andy@33673 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10051 Create a development branch.


git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/andy@33677 251d0590-4201-4cf1-90de-194747b24ca1