Add Russian help and level files

These two commits are the import of the files mentionned in colobot/colobot#247 that are the Russian translation for help and level files, in the correct unicode format.

As I don't read Russian (and the Google translation is not sufficient), I don't know if these files are licensed in a GPL3-compatible way (or if they have been released as part of the Epsitec GPL-3 release).

Therefore please only merge after having checked (in Russian :-) ) that the files are compatible, or take responsibility for the merge. 

Cheers, OdyX