WebDAV: Store properties of resources
Each WebDAV resource may have additional attributes like DAV:getetag, DAV:getcontenttype etc. These attributes are stored and managed by TElWebDAVServer for each resource automatically using file system adapter's WriteFileTag(), ReadFileTag(), DeleteFileTag() methods. So these methods should be implemented for custom adapters. The implementation may store the attributes in database, file or NTFS file streams etc.