Merge changes made in Gnus trunk.

Merge changes made in Gnus trunk.

gnus.texi (Article Date): Clarify gnus-article-update-date-headers.
gnus-msg.el (gnus-inews-add-send-actions): Restore the winconf name after exit.
gnus-sum.el (gnus-summary-show-article): When called with t as the value, show the raw article.
nnimap.el (nnimap-open-connection-1): Revert last change, since auth-source now accepts numbers.
auth-source.el (auth-source-netrc-parse): Accept a number as the port spec, too.
 (auth-source-ensure-strings): New function.
gnus-art.el (gnus-article-update-date-headers): Doc fix.
 (gnus-article-setup-buffer): Always restart the date timer so that user changes to the frequency is respected.
nnimap.el (nnimap-open-connection-1): auth-source expects strings as port numbers, so make sure it gets that if nnimap-server-port is explicit.
nnimap.el (nnimap-inbox): Doc fix.