nat: Add a test case for the connection tracking

This test case tests connectiont tracking by sending
a CR, getting a CC, sending a DTAP, receiving a DTAP,
receiving a RLSD, sending a RLC. It verifies that the
messages are properly patched specially the references
at the BSC.
diff --git a/openbsc/tests/bsc-nat/Makefile.am b/openbsc/tests/bsc-nat/Makefile.am
index 0a47e37..f0d21f0 100644
--- a/openbsc/tests/bsc-nat/Makefile.am
+++ b/openbsc/tests/bsc-nat/Makefile.am
@@ -1,7 +1,12 @@
 INCLUDES = $(all_includes) -I$(top_srcdir)/include
-AM_CFLAGS=-Wall -ggdb3
+AM_CFLAGS=-Wall -ggdb3 $(LIBOSMOCORE_CFLAGS)
+
+EXTRA_DIST = bsc_data.c
 
 noinst_PROGRAMS = bsc_nat_test
 
-bsc_nat_test_SOURCES = bsc_nat_test.c $(top_srcdir)/src/nat/bsc_filter.c
-bsc_nat_test_LDADD = $(top_builddir)/src/libbsc.a $(top_builddir)/src/libsccp.a
+bsc_nat_test_SOURCES = bsc_nat_test.c \
+			$(top_srcdir)/src/nat/bsc_filter.c \
+			$(top_srcdir)/src/nat/bsc_sccp.c \
+			$(top_srcdir)/src/nat/bsc_nat_utils.c
+bsc_nat_test_LDADD = $(top_builddir)/src/libbsc.a $(top_builddir)/src/libsccp.a $(LIBOSMOCORE_LIBS)