docs/gst/Makefile.am: Ignore a few more internal headers

docs/gst/Makefile.am: Ignore a few more internal headers

Original commit message from CVS:
* docs/gst/Makefile.am: Ignore a few more internal headers
* docs/gst/gstreamer-docs.sgml: Remove old sections
* docs/gst/gstreamer-sections.txt: Remove old sections
* docs/gst/tmpl/gstobject.sgml: update
* docs/gst/tmpl/gstplugin.sgml: update
* docs/gst/tmpl/gstpluginfeature.sgml: update
* docs/random/ds/0.9-suggested-changes: update.
* gst/Makefile.am: remove memchunk and trashstack, since they're
not used.
* gst/gst.c: (gst_deinit): rename gst_registry_deinit to _cleanup
* gst/gst.h: don't include some headers
* gst/gstchildproxy.c: add gstmarshal.h
* gst/gstclock.c: Don't use memchunks
* gst/gstminiobject.c: Add some docs
* gst/gstobject.c: remove DESTROYED flag, since it's redundant
* gst/gstobject.h: same
* gst/gstplugin.c: include gstmacros.h
* gst/gstplugin.h: don't include gstmacros.h, since it's private
* gst/gstquery.c: don't use memchunks
* gst/gstregistry.c: rename gst_registry_deinit()
* gst/gstregistry.h: same