Add an option to allow everyone to the network.

This should move out of gsm_04_08 and the accept, reject
policy should be controllable by the higher levels.
diff --git a/include/openbsc/gsm_04_08.h b/include/openbsc/gsm_04_08.h
index 424d4aa..6b0517e 100644
--- a/include/openbsc/gsm_04_08.h
+++ b/include/openbsc/gsm_04_08.h
@@ -375,6 +375,7 @@
 struct msgb;
 struct gsm_bts;
 
+void gsm0408_allow_everyone(int allow);
 int gsm0408_rcvmsg(struct msgb *msg);
 void gsm0408_generate_lai(struct gsm48_loc_area_id *lai48, u_int16_t mcc, 
 		u_int16_t mnc, u_int16_t lac);