Russian lang.

* Source files updated
* Built and tested to looks nice in most places
* Bad news: Russian lang has more complex plural rules
and "sexual" verb endings, that currently solved
as "сообщения(-ий)" or "сделал(-а)"
* It should be done in more nice way later

At https://www.transifex.com/projects/p/telegram-desktop/ 33 langs
requested, but no one accepted. After Russian will be there,
I can sent translation there too. Or it's could be extracted
from lang_ru.strings there by tx tool.

For translation thanks to Alla Ustimenko http://angloved.ru