client: add an optional FSM interface

the client API is not very intuitive and requires a lot of extra
care when it is used from an osmo-fsm.

- Add an FSM that permits comfortable handling of an MGCP
  connection.

Change-Id: I887ce0c15a831dffeb6251a975337b83942af566
diff --git a/src/libosmo-mgcp-client/Makefile.am b/src/libosmo-mgcp-client/Makefile.am
index 1e4e764..a3a920b 100644
--- a/src/libosmo-mgcp-client/Makefile.am
+++ b/src/libosmo-mgcp-client/Makefile.am
@@ -29,6 +29,7 @@
 libosmo_mgcp_client_la_SOURCES = \
 	mgcp_client.c \
 	mgcp_client_vty.c \
+	mgcp_client_fsm.c \
 	$(NULL)
 
 libosmo_mgcp_client_la_LDFLAGS = $(AM_LDFLAGS) -version-info $(MGCP_CLIENT_LIBVERSION)