Introduce libsmpputil

As part of preparation for libosmo-netif migration let's move common SMPP code
into separate build-time library and use it for both smpp_mirror and OsmoMSC
renaming the files if necessary.

While at it we also fix id/password legth limits in smpp_mirror and drop unused
fields from ESME struct.

Related: OS#5568
Change-Id: I61910651bc7c188dc2fb67d96189a66a47e7e8fb
diff --git a/src/utils/Makefile.am b/src/utils/Makefile.am
index cb0faf6..75a2926 100644
--- a/src/utils/Makefile.am
+++ b/src/utils/Makefile.am
@@ -34,12 +34,16 @@
 
 smpp_mirror_CFLAGS = \
 	$(LIBOSMOCORE_CFLAGS) \
+	$(LIBOSMOSCCP_CFLAGS) \
+	$(LIBOSMOMGCPCLIENT_CFLAGS) \
 	$(LIBSMPP34_CFLAGS) \
 	$(NULL)
 
 smpp_mirror_LDADD = \
+	$(top_builddir)/src/libsmpputil/libsmpputil.a \
 	$(LIBOSMOCORE_LIBS) \
 	$(LIBOSMOGSM_LIBS) \
+	$(LIBOSMONETIF_LIBS) \
 	$(LIBSMPP34_LIBS) \
 	$(NULL)
 endif