Add FileService and fileViewModel
Merge remote-tracking branch 'remotes/origin/Slava' into Vadzim

Conflicts:
	FileExchange/FileExchange.BLL/FileExchange.BLL.csproj
	FileExchange/FileExchange.WebUI/App_Data/FileExchange.mdf
	FileExchange/FileExchange.WebUI/App_Data/FileExchange_log.ldf
	FileExchange/FileExchange.v11.suo