l10n: Russian localization started

All work will be done in [git-po-ru Transifex project](https://www.transifex.com/projects/p/git-po-ru/) and then uploaded into my Github clone. 
Sorry but Transifex creates useless header in translated po:
># SOME DESCRIPTIVE TITLE.
># Copyright (C) YEAR THE PACKAGE'S COPYRIGHT HOLDER
># This file is distributed under the same license as the PACKAGE package.
I hope this is not a problem.