Merge changes made in Gnus trunk.

Merge changes made in Gnus trunk.

shr.el: Implement table rendering.
shr.el (shr-make-table): Tweak table generation.
shr.el (shr-make-table): Fix typo.
nnimap.el (nnimap-open-connection): Allow tls as a synonym for ssl.
gnus-util.el (gnus-emacs-completing-read): Mapcar collection to list, for XEmacs.
nnimap.el (nnimap-close-server): Implement.
gnus-salt.el: Remove all gnus-carpal stuff -- it's not useful.
nnir.el (nnir-run-imap): Remove spurious space in search string.
message.el (message-idna-to-ascii-rhs-1): Don't bug out on addresses without @ signs.
gnus-sum.el (gnus-widen-article-window): New variable.
shr.el (browse-url): Required.
shr.el (shr-ensure-paragraph): Don't insert a new newline after empty-ish lines.
shr.el (shr-show-alt-text, shr-browse-image): New commands.
gravatar.el (gravatar-retrieved): kill buffer when retrieved.
shr.el (shr-browse-url, shr-copy-url): New commands.
shr.el (shr-render-td): Protect against too-wide text.
spam-report.el (spam-report-url-ping-plain): Don't query about killing the process.
nnimap.el (nnimap-finish-retrieve-group-infos): Message while waiting for data.
shr.el (shr-tag-blockquote): Ensure paragraph after quote, too.
mml-smime.el: Fix gnus-completing-read usage.
shr.el (shr-get-image-data): Ensure against the cache file missing.
nnimap.el (nnimap-open-connection): Give an error if nnimap-stream is unknown.