Implement IuCS (large refactoring and addition)

osmo-nitb becomes osmo-msc
add DIUCS debug log constant
add iucs.[hc]
add msc vty, remove nitb vty
add libiudummy, to avoid linking Iu deps in tests
Use new msc_tx_dtap() instead of gsm0808_submit_dtap()
libmgcp: add mgcpgw client API
bridge calls via mgcpgw

Enable MSC specific CTRL commands, bsc_base_ctrl_cmds_install() still needs to
be split up.

Change-Id: I5b5b6a9678b458affa86800afb1ec726e66eed88
diff --git a/include/openbsc/mgcp_internal.h b/include/openbsc/mgcp_internal.h
index 7c89d10..b58eb9b 100644
--- a/include/openbsc/mgcp_internal.h
+++ b/include/openbsc/mgcp_internal.h
@@ -28,14 +28,6 @@
 
 #define CI_UNUSED 0
 
-enum mgcp_connection_mode {
-	MGCP_CONN_NONE = 0,
-	MGCP_CONN_RECV_ONLY = 1,
-	MGCP_CONN_SEND_ONLY = 2,
-	MGCP_CONN_RECV_SEND = MGCP_CONN_RECV_ONLY | MGCP_CONN_SEND_ONLY,
-	MGCP_CONN_LOOPBACK  = 4 | MGCP_CONN_RECV_SEND,
-};
-
 enum mgcp_trunk_type {
 	MGCP_TRUNK_VIRTUAL,
 	MGCP_TRUNK_E1,
@@ -340,3 +332,5 @@
 		return endp->cfg->bts_ports.bind_addr;
 	return endp->cfg->source_addr;
 }
+
+int mgcp_msg_terminate_nul(struct msgb *msg);