split off osmo-mgw: remove files, apply build, rename

Add vty and logging previously used from libcommon

Rename libmgcp to libosmo-legacy-mgcp and install.

Use DLMGCP, not DMGCP.

Slim down the public mgcpgw_client API, move all elements not actually used by
current callers to private headers / static c.

Depends: libosmocore I09c587e2d59472cbde852d467d457254746d9e67
Change-Id: I71a0a16ebaaef881c34235849601fc40aa12cfd7
diff --git a/include/Makefile.am b/include/Makefile.am
index 3234e62..73b1b3e 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -1,8 +1,10 @@
 SUBDIRS = \
-	openbsc \
+	osmocom \
 	$(NULL)
 
-noinst_HEADERS = \
-	mISDNif.h \
-	compat_af_isdn.h \
+nobase_include_HEADERS = \
+	osmocom/legacy_mgcp/mgcp.h \
+	osmocom/legacy_mgcp/mgcp_internal.h \
+	osmocom/legacy_mgcp/mgcpgw_client.h \
+	osmocom/legacy_mgcp/osmux.h \
 	$(NULL)