docs: add missing files for distribution

* add some documentation files in docs/design
 * add docs/list-ulink.xsl so check in docs/manual works

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=719814

docs/Makefile.am

@@ -21,7 +21,7 @@ DIST_SUBDIRS = design gst libs plugins faq manual pwg slides xsl
 
 EXTRA_DIST = \
 	manuals.mak htmlinstall.mak \
-	image-png image-pdf image-eps url.entities version.entities.in
+	image-png image-pdf image-eps url.entities version.entities.in list-ulink.xsl
 
 upload:
 	@if test "x$(SUBDIRS)" != x; then for a in $(SUBDIRS); do cd $$a; make upload; cd ..; done; fi

docs/design/Makefile.am

@@ -1,13 +1,18 @@
 
 EXTRA_DIST = \
 	draft-klass.txt \
+	draft-metadata.txt \
 	draft-push-pull.txt \
 	draft-tagreading.txt \
+	draft-tracing.txt \
 	part-activation.txt \
 	part-buffering.txt \
+	part-bufferpool.txt \
+	part-buffer.txt \
 	part-caps.txt \
 	part-clocks.txt \
 	part-context.txt \
+	part-controller.txt \
 	part-conventions.txt \
 	part-dynamic.txt \
 	part-element-sink.txt \
@@ -23,12 +28,17 @@ EXTRA_DIST = \
 	part-gstpipeline.txt \
 	part-latency.txt \
 	part-live-source.txt \
+	part-memory.txt \
 	part-messages.txt \
+	part-meta.txt \
+	part-miniobject.txt \
 	part-missing-plugins.txt \
 	part-MT-refcounting.txt \
 	part-negotiation.txt \
 	part-overview.txt \
 	part-preroll.txt \
+	part-probes.txt \
+	part-progress.txt \
 	part-push-pull.txt \
 	part-qos.txt \
 	part-query.txt \