Fix malformed-HTML fallout across RSS, link rewriting, and flash messaging

Editors' TinyMCE output can contain unclosed void elements like <br>,
which is valid HTML5 but invalid XML -- three different places assumed
the stricter rule and broke or silently misbehaved on the looser one.
The Atom feed's <content type="xhtml"> block required real, well-formed
XML structure but was handed a raw, unescaped body string; switched to
type="html" with CGI.escapeHTML, matching how title/summary already
handle the same content. rewrite_links_in_body used libxml's strict XML
parser to rewrite internal links to be locale-prefixed, which raised on
exactly this class of malformed markup -- silently, since the whole
method was wrapped in rescue; nil, meaning the link rewrite (not the
save) quietly failed with no error anywhere. Replaced with Nokogiri's
lenient HTML parser, which repairs malformed void elements rather than
rejecting them; also drops the bare rescue now that the actual failure
mode it was guarding against shouldn't occur, and fixes two adjacent
bugs found while in this method: a typo'd /sytem/uploads/ regex that
could never match, and a missing https:// exclusion alongside the
existing http:// one.

Also addresses stale flash messaging surfaced while testing the above:
update's save confirmation was being clobbered by edit's own "locked
and ready" notice on the very next request, since nothing distinguished
a fresh lock acquisition from a redirect back after saving. The save
confirmation now names the next step (publish from Status) and flags a
stale translation if one exists, using Page#outdated_translations?,
already present but previously unused by any controller.

1 files changed, 9 insertions, 0 deletions

diff --git a/public/stylesheets/admin.css b/public/stylesheets/admin.css
index f00a658..3f95b0c 100644
--- a/public/stylesheets/admin.css
+++ b/public/stylesheets/admin.css
@@ -193,6 +193,15 @@ input[type=radio] {
   margin-left: 5px;
 }
 
+#flash a {
+  text-decoration: underline;
+  -webkit-text-decoration-style: wavy;
+  text-decoration-style: wavy;
+  text-decoration-color: #b0b0b0;
+  text-decoration-thickness: 1px;
+  text-underline-offset: 2px;
+}
+
 #flash span {
   letter-spacing: 1px;
   margin-right: 10px;