import gsup_client.c as new libosmo-gsup-client

This imports the code from osmo-msc 6afef893e17bce67e4d4119acd34d480ed03ba77
with minimal changes to make it compile.  Symbol renaming ot osmo_
prefix is done separately in a follow-up patch to have a as-clean-as-possible
import first.

Requires: libosmocore.git Change-Id Ie36729996abd30b84d1c30a09f62ebc6a9794950
Change-Id: Ief50054ad135551625b684ed8a0486f7af0b2940
diff --git a/configure.ac b/configure.ac
index cedba45..16c8b51 100644
--- a/configure.ac
+++ b/configure.ac
@@ -99,6 +99,9 @@
 	Makefile
 	doc/Makefile
 	src/Makefile
+	src/gsupclient/Makefile
+	include/Makefile
+	libosmo-gsup-client.pc
 	sql/Makefile
 	tests/Makefile
 	tests/auc/Makefile