ticket:10342: derb modernisation

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/srl@34128 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10342: derb modernisation - use ustdio instead of raw stuff. TODO: windows.

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/srl@34129 251d0590-4201-4cf1-90de-194747b24ca1