debugging: Add enough to choke a mule

Added to:
 * bridges/bridge_softmix.c
 * channels/chan_pjsip.c
 * include/asterisk/res_pjsip_session.h
 * main/channel.c
 * res/res_pjsip_session.c

There NO functional changes in this commit.

Change-Id: I06af034d1ff3ea1feb56596fd7bd6d7939dfdcc3

include/asterisk/res_pjsip_session.h

@@ -121,6 +121,10 @@ struct ast_sip_session_media {
 	unsigned int changed;
 	/*! \brief Remote media stream label */
 	char *remote_mslabel;
+	/*! \brief Remote stream label */
+	char *remote_label;
+	/*! \brief Stream name */
+	char *stream_name;
 };
 
 /*!