Feature/rest gamehist service

@Mequrel , @mgruszka , @p4r4noj4 , @Adebski please verify. 
In my personal opinion, we should store players initial positions in map dictionary from https://confluence.iisg.agh.edu.pl/display/ietanks/Front-end 's /api/game/{gameId} POST method, because events store only relative position changes. This should be discussed with fron-end guys @p4r4noj4 , @mgruszka .

It may be nitpicking but I think that having nicely formatted code helps with the readability. If you wanted to communicate something like that you could add comment if you think that information is important. 

Someone else may also misinterpret why the semicolon was placed where it was placed.