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/doc/examples/osmo-bsc_mgcp/mgcp.cfg b/doc/examples/osmo-bsc_mgcp/mgcp.cfg
index 791497f..2622d23 100644
--- a/doc/examples/osmo-bsc_mgcp/mgcp.cfg
+++ b/doc/examples/osmo-bsc_mgcp/mgcp.cfg
@@ -7,13 +7,13 @@
  no login
 !
 mgcp
-!  local ip 213.167.134.14
-  bts ip 172.16.252.43
-  bind ip 127.0.0.1
+  !local ip 192.168.0.132
+  !bts ip 192.168.0.124
+  !bind ip 192.168.0.132
   bind port 2427
   rtp base 4000
   rtp force-ptime 20
   sdp audio payload number 98
   sdp audio payload name AMR/8000
   number endpoints 31
-  loop 1
+  no rtcp-omit