ticket:10012: C changes from Bing Long.

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/yoshito@34330 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10012: Updated setDetactableCharset, etc..

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/yoshito@34337 251d0590-4201-4cf1-90de-194747b24ca1