ticket:10653: Fixed a thread safety problem in SimpleDateFormat.

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk@34992 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10577: Added a test case in ICU4C to check if the calendar factory method uses locale's region to initialize week data. ICU4C library code is working fine, so no changes in the library code.

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk@35002 251d0590-4201-4cf1-90de-194747b24ca1