sgsn: Integrate subscriber handling into the SGSN

This commit adds a new authorization policy 'remote' and uses
the subscriber cache for authorization when this policy is being used.

Note that there is no remote backend implemented yet. After the
IMSI/IMEI have been acquired, a request would be sent to the remote
peer. The attach/auth-ciph procedure continues when authorization
info has been received from the peer. This means, that
gprs_subscr_update() must be called then to tell the GMM layer
that it can proceed. A later commit will add VTY commands to do this
manually.

Sponsored-by: On-Waves ehf
diff --git a/openbsc/tests/sgsn/Makefile.am b/openbsc/tests/sgsn/Makefile.am
index 0e5d009..970311d 100644
--- a/openbsc/tests/sgsn/Makefile.am
+++ b/openbsc/tests/sgsn/Makefile.am
@@ -7,7 +7,8 @@
 
 sgsn_test_SOURCES = sgsn_test.c
 sgsn_test_LDFLAGS = \
-	-Wl,--wrap=sgsn_update_subscriber_data
+	-Wl,--wrap=sgsn_update_subscriber_data \
+	-Wl,--wrap=gprs_subscr_request_update
 
 sgsn_test_LDADD = \
 	$(top_builddir)/src/gprs/gprs_llc_parse.o \