int Ns_ParseUrl( char *url, char **pprotocol, char **phost, char **pport, char **ppath, char **ptail );
Parse a URL into its component parts. Pointers to the protocol, host, port, path, and "tail" (last path element) will be set by reference in the passed-in pointers. The passed-in url will be modified. Return NS_OK on success or NS_ERROR on failure.