Misc bugfixes made in Gnus master

Misc bugfixes made in Gnus master

2014-01-31 Alex Schroeder <alex@gnu.org> (tiny change)
  * gnus-tut.txt (Message-ID): Typo fix (bug#15556).
2014-01-31 Dave Abrahams <dave@boostpro.com>
  * gnus-salt.el (gnus-tree-highlight-article): Don't move point around
  in the summary buffer (bug#13769).
2014-01-31 Lars Ingebrigtsen <larsi@gnus.org>
  * gnus-art.el (gnus-article-setup-buffer): Refresh the summary buffer
  name if we're using a single article buffer. Otherwise, it may point
  to a killed buffer (bug#13756).
2014-01-30 Lars Ingebrigtsen <larsi@gnus.org>
  * nnmail.el (nnmail-split-it): Instead of redoing the search to restore
  the match data, just save and restore it explictly (bug#12375).
  * gnus-sum.el (gnus-summary-read-group-1): Initialize the spam code if
  that's needed.
  * spam.el (spam-initialize): Allow calling repeatedly, but only run the
  the code once (bug#9069).