Added functions to api controllers for get by id and put data.
Added file statistics.
Added logic for getting tags information.
Merge remote-tracking branch 'remotes/origin/Vika' into Vadzim

Conflicts:
	FileExchange/FileExchange.BLL/Concrete/FileService.cs
	FileExchange/FileExchange.BLL/Interfaces/IFileService.cs
	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/Controllers/AdminController.cs
	FileExchange/FileExchange.WebUI/FileExchange.WebUI.csproj
	FileExchange/FileExchange.WebUI/Views/Shared/_Layout.cshtml
	FileExchange/FileExchange.v11.suo
	FileExchange/FileExchange.v12.suo