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/src/gprs/sgsn_vty.c b/src/gprs/sgsn_vty.c
index 1cefe37..888f53a 100644
--- a/src/gprs/sgsn_vty.c
+++ b/src/gprs/sgsn_vty.c
@@ -44,6 +44,12 @@
 
 #include <pdp.h>
 
+#include "../../bscconfig.h"
+
+#ifdef BUILD_IU
+#include <openbsc/iu.h>
+#endif
+
 static struct sgsn_config *g_cfg = NULL;
 
 const struct value_string sgsn_auth_pol_strs[] = {
@@ -297,6 +303,10 @@
 	} else
 		vty_out(vty, " no compression v42bis%s", VTY_NEWLINE);
 
+#ifdef BUILD_IU
+	iu_vty_config_write(vty, " ");
+#endif
+
 	return CMD_SUCCESS;
 }
 
@@ -1284,6 +1294,10 @@
 	install_element(SGSN_NODE, &cfg_no_comp_v42bis_cmd);
 	install_element(SGSN_NODE, &cfg_comp_v42bis_cmd);
 	install_element(SGSN_NODE, &cfg_comp_v42bisp_cmd);
+
+#ifdef BUILD_IU
+	iu_vty_init(SGSN_NODE, &g_cfg->iu.rab_assign_addr_enc);
+#endif
 	return 0;
 }