Add Russian localization

 - add Russian localization (both .strings and .xib)
 - add missed Localizable keys for some dialogs:  

> «`Server not found`»  
> «`Full screen is not supported on Mac OS X 10.5`»  
> «`Restore default settings`»  
> «`Restore default resolutions`»  

 - fix misspeled Localizable key "Active session" --> "Active Sessions"