Added additional logic to include range header in HEAD request in order ...

...to determine content length if content-length header is not returned by server.  Also include check of timeseekrange header when determining size.  If size is determined by content-range or timeseekrange headers, update appropriate data members to reflect that content size is known and that seeking is supported.  Also added more info level logging including a log of the HTTP request and response.

Including @s-maynard for review