misc: Introduce a script tha generates the VTY reference

Update/Move/Create example configuration files for NiTB, BSC,
MGCP, NAT and the GbProxy. Create a script that starts, generates
the vty reference and terminates the application.
diff --git a/openbsc/doc/examples/osmo-bsc_mgcp/mgcp.cfg b/openbsc/doc/examples/osmo-bsc_mgcp/mgcp.cfg
index 678f546..c46b46d 100644
--- a/openbsc/doc/examples/osmo-bsc_mgcp/mgcp.cfg
+++ b/openbsc/doc/examples/osmo-bsc_mgcp/mgcp.cfg
@@ -9,7 +9,7 @@
 mgcp
 !  local ip 213.167.134.14
   bts ip 172.16.252.43
-  bind ip 213.167.134.141
+  bind ip 127.0.0.1
   bind port 2427
   bind early 1
   rtp base 4000