Add russian translation

I'm not sure that it's fully correct russian translation. In russian language correct term for "follow" is "следить" or "читать", but I choose term "подписаться" (correct translation for "подписаться" is "subscribe") because it sounds better in russian language.

Also translation's for "object_type_\*" choosed in assumption that "object_type_\*" strings would be used only in 

> \<!-- 1 = actor, 2 = verb, 3 = object, 4 = target of a reply --\>
> \<string name="format_string_activity"\>%1$s %2$s %3$s\</string\>
> \<string name="format_string_reply"\>%1$s %2$s %3$s in reply to %4$s\</string\>

messages. Because "Somebody create collection" translate in russian as "Кто-то создал коллеки_ю_", but "collection" translates as "коллекци_я_" (see to last char of word "коллекци_я_").

But despite this problems I use this translation.