Introduce libosmo-ranap.so as shared RANAP lib

This shared RANAP library will be used not only by hnbgw, but also by
OsmoCSCN, OsmoSGSN.
diff --git a/src/tests/Makefile.am b/src/tests/Makefile.am
index 18490be..973cf3f 100644
--- a/src/tests/Makefile.am
+++ b/src/tests/Makefile.am
@@ -6,10 +6,6 @@
 
 HNBAP_FILES = $(top_builddir)/src/hnbap_common.c $(top_builddir)/src/hnbap_decoder.c $(top_builddir)/src/hnbap_encoder.c
 RUA_FILES = $(top_builddir)/src/rua_common.c $(top_builddir)/src/rua_decoder.c $(top_builddir)/src/rua_encoder.c
-RANAP_FILES = $(top_builddir)/src/ranap_common.c \
-	      $(top_builddir)/src/ranap_decoder.c \
-	      $(top_builddir)/src/ranap_encoder.c \
-	      $(top_builddir)/src/ranap_msg_factory.c
 HELPER_FILES = $(top_builddir)/src/iu_helpers.c $(top_builddir)/src/asn1helpers.c
 
 test_helpers_SOURCES = $(HELPER_FILES) test-helpers.c
@@ -18,14 +14,14 @@
 test_hnbap_SOURCES = $(HELPER_FILES) $(top_builddir)/src/hnbap_common.c $(top_builddir)/src/hnbap_decoder.c test-hnbap.c test_common.c
 test_hnbap_LDADD = $(COMMON_LIBS) $(top_builddir)/src/hnbap/libosmo-asn1-hnbap.a
 
-hnb_test_SOURCES = $(HELPER_FILES) $(HNBAP_FILES) $(RUA_FILES) $(RANAP_FILES) hnb-test.c rua_helper.c test_common.c
-hnb_test_LDADD = $(COMMON_LIBS) $(top_builddir)/src/hnbap/libosmo-asn1-hnbap.a $(top_builddir)/src/rua/libosmo-asn1-rua.a $(top_builddir)/src/ranap/libosmo-asn1-ranap.a
+hnb_test_SOURCES = $(HELPER_FILES) $(HNBAP_FILES) $(RUA_FILES) hnb-test.c rua_helper.c test_common.c
+hnb_test_LDADD = $(COMMON_LIBS) $(top_builddir)/src/hnbap/libosmo-asn1-hnbap.a $(top_builddir)/src/rua/libosmo-asn1-rua.a $(top_builddir)/src/libosmo-ranap.la
 
 test_ranap_SOURCES = $(HELPER_FILES) $(RANAP_FILES) test-ranap.c test_common.c
-test_ranap_LDADD = $(COMMON_LIBS) $(top_builddir)/src/ranap/libosmo-asn1-ranap.a
+test_ranap_LDADD = $(COMMON_LIBS) $(top_builddir)/src/libosmo-ranap.la
 
 dummy_cn_SOURCES = $(HELPER_FILES) $(RANAP_FILES) test_common.c dummy_cn_sua.c ranap_common_cn.c
-dummy_cn_LDADD = $(COMMON_LIBS) $(top_builddir)/src/ranap/libosmo-asn1-ranap.a
+dummy_cn_LDADD = $(COMMON_LIBS) $(top_builddir)/src/libosmo-ranap.la
 
 # The `:;' works around a Bash 3.2 bug when the output is not writeable.
 $(srcdir)/package.m4: $(top_srcdir)/configure.ac