Extract file downloading in file service, add user downloading rate limit
Crazy merge
Rewrite file managing
Merge remote-tracking branch 'remotes/origin/Slavaa' into Vadzim

Conflicts:
	FileExchange/FileExchange.BLL/Concrete/FileService.cs
	FileExchange/FileExchange.BLL/Interfaces/IFileService.cs
	FileExchange/FileExchange.Common/Constants/Constants.cs
	FileExchange/FileExchange.DAL/FileExchange.DAL.csproj
	FileExchange/FileExchange.WebUI/App_Data/FileExchange.mdf
	FileExchange/FileExchange.WebUI/App_Data/FileExchange_log.ldf
	FileExchange/FileExchange.WebUI/App_Start/AutomapperConfig.cs
	FileExchange/FileExchange.WebUI/App_Start/BundleConfig.cs
	FileExchange/FileExchange.WebUI/Content/FileExchangeStyles.css
	FileExchange/FileExchange.WebUI/Controllers/FileController.cs
	FileExchange/FileExchange.WebUI/FileExchange.WebUI.csproj
	FileExchange/FileExchange.WebUI/Scripts/Views/File/add-file.js
	FileExchange/FileExchange.WebUI/ViewModels/FileViewModel/UploadFileViewModel.cs
	FileExchange/FileExchange.WebUI/Views/Admin/Index.cshtml
	FileExchange/FileExchange.WebUI/Views/File/AddFile.cshtml
	FileExchange/FileExchange.WebUI/Views/File/MyFiles.cshtml
	FileExchange/FileExchange.WebUI/Views/File/_LinkForFilePartial.cshtml
	FileExchange/FileExchange.WebUI/Views/Shared/_Layout.cshtml
	FileExchange/FileExchange.WebUI/Web.config
	FileExchange/FileExchange.v11.suo
	FileExchange/FileExchange.v12.suo
Fix bugs after merge