ndn-cxx: Add ndn-cxx-dbg package with debug symbols of ndn-cxx

Change-Id: Ia506b9a972ce368e80271fe649956c46958b79a6
Refs: #11
diff --git a/ndn-cxx/debian/rules b/ndn-cxx/debian/rules
index 002775d..d879ec1 100755
--- a/ndn-cxx/debian/rules
+++ b/ndn-cxx/debian/rules
@@ -36,3 +36,7 @@
 	rm -f docs/*.pyc
 
 override_dh_auto_test:
+
+.PHONY: override_dh_strip
+override_dh_strip:
+	dh_strip --dbg-package=ndn-cxx-dbg