Merge changes made in Gnus trunk.

Merge changes made in Gnus trunk.

shr.el: Rearrange function order to be more logical.
gnus-faq.texi: Remove reference to my.gnus.org
message.el (message-change-subject): Remove 404 URL in a comment.
nnir.el: Fix Swish-E URL.
nnir.el: Fix Namazu URL.
nnrss.el (nnrss-check-group): Remove 404 URL in comment.
nnrss.el (nnrss-discover-feed): Remove 404 URL in docstring.
gnus-faq.texi (FAQ 5-5): Fix Flyspell URL.
gnus-faq.texi (FAQ 7-1): Fix getmail URL.
gnus.texi (Comparing Mail Back Ends): Remove broken link and allusion to ReiserFS.
nnimap.el (nnimap-open-connection): Prepare to support open-gnutls-stream.
shr.el (shr-insert): Get 'space transition right.
message.texi: Remove reference to gpg-2comp.