Make gcc happy and remove a couple of warnings

Remove the callbacks from gsm_network for now. A set of different
callbacks will be back. E.g. when the paging is completed, when the
Q.931 like call handling is there...

Remove var's or move them into #if 0, remove unused stuff that looks
like we do not need it anytime soon or #if 0 them, move stuff around.
diff --git a/include/openbsc/misdn.h b/include/openbsc/misdn.h
index 09dc5ba..51932c2 100644
--- a/include/openbsc/misdn.h
+++ b/include/openbsc/misdn.h
@@ -23,5 +23,6 @@
 int mi_setup(struct gsm_bts *bts, int cardnr, 
 	     void (cb)(int event, struct gsm_bts *bts));
 void mi_set_pcap_fd(int fd);
+int _abis_nm_sendmsg(struct msgb *msg);
 
 #endif