mgw: Initial IPv6 support

This commit contains the bulky work of moving all address parsing to
support IPv6 together with IPv4.
Some specific patches required for full IPv6+IPv4 support requiring
behavioral changes come after this one.

Full Osmux IPv6 support is left out of the scope of this patch.

Depends: libosmocore.git Ie07a38b05b7888885dba4ae795e9f3d9a561543d (> 1.4.0)
Depends: libosmocore.git I59bf4b4b3ed14766a5a5285923d1ffa9fc8b2294 (> 1.4.0)
Change-Id: I504ca776d88fd852bbaef07060c125980db3fdd7
diff --git a/include/osmocom/mgcp/mgcp_endp.h b/include/osmocom/mgcp/mgcp_endp.h
index 065494f..14cae25 100644
--- a/include/osmocom/mgcp/mgcp_endp.h
+++ b/include/osmocom/mgcp/mgcp_endp.h
@@ -26,7 +26,7 @@
 #include <osmocom/core/msgb.h>
 #include <osmocom/gsm/i460_mux.h>
 
-struct sockaddr_in;
+struct sockaddr;
 struct mgcp_conn;
 struct mgcp_conn_rtp;
 struct mgcp_endpoint;
@@ -42,7 +42,7 @@
 struct osmo_rtp_msg_ctx {
 	int proto;
 	struct mgcp_conn_rtp *conn_src;
-	struct sockaddr_in *from_addr;
+	struct osmo_sockaddr *from_addr;
 };
 
 #define OSMO_RTP_MSG_CTX(MSGB) ((struct osmo_rtp_msg_ctx*)(MSGB)->cb)