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.
Addressed issues from code review including rewrite of gst_soup_http_src_determine_size() to simplify, got rid of timeseekrange handling in HEAD response since it is not included in HEAD request and other misc fixups.
Put "bytes" back into format string to have additional checking on header value.  Replaced size=0 with free() and return.
Merge pull request #2 from cablelabs/determine_size

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