Merge changes made in Gnus master

Merge changes made in Gnus master

2013-07-06 Lars Ingebrigtsen <larsi@gnus.org>
* gnus.texi (Group Parameters): Mention regexp
  substitutions (bug#11688).

2013-07-06 Nathan Trapuzzano <nbtrap@nbtrap.com> (tiny change)
* gnus.texi (Generic Marking Commands): Fix grammar (bug#13368).

2013-07-06 Lars Ingebrigtsen <larsi@gnus.org>
* gnus.texi (Emacsen): Fix version.
* gnus-faq.texi (FAQ 1-6): Mention the correct Emacs version.

2013-07-06 Lars Ingebrigtsen <larsi@gnus.org>
* gnus-art.el (gnus-block-private-groups): Allow `global' methods to
  display images.
* gnus.el (gnus-valid-select-methods): Mark nnrss as global.
* message.el (message-cancel-news): According to
  <mailman.216.1372942181.12400.help-gnu-emacs@gnu.org>, "cancel" is
  preferred over "cmsg cancel" in the Subject.
* nnir.el (nnir-engines): Note that the group specs are regexps
  (bug#13238).
* gnus-msg.el (gnus-copy-article-buffer): If the article buffer has
  gotten read-only text properties, ensure that those aren't heeded when
  copying stuff over (bug#13434).
* mm-view.el (mm-inline-text-html): Don't bug out on multipart messages
  (bug#13762).