Extract file downloading from GetFile action, remove path from infofileviewmodel
Add file throttling.
Merge remote-tracking branch 'remotes/origin/Slavaa' into Vadzim

Conflicts:
	FileExchange/FileExchange.BLL/Concrete/FileService.cs
	FileExchange/FileExchange.WebUI/Controllers/FileController.cs
	FileExchange/FileExchange.WebUI/Controllers/HomeController.cs
	FileExchange/FileExchange.WebUI/ViewModels/FileViewModel/DownloadFileViewModel.cs
	FileExchange/FileExchange.WebUI/Views/File/AddFile.cshtml
	FileExchange/FileExchange.WebUI/Views/File/AllFiles.cshtml
	FileExchange/FileExchange.v12.suo