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/.gitignore b/.gitignore
index 919be0f..cf5542d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -58,6 +58,7 @@
 src/gprs/osmo-gtphub
 src/osmo-bsc_nat/osmo-bsc_nat
 src/libcommon/gsup_test_client
+src/osmo-msc/osmo-msc
 
 #tests
 tests/testsuite.dir