There was a problem with wiki pages in the HTML markup syntax. If they
contain a link and the link text has a URL in it, that URL was converted
into another link. But it was not correctly nested and it caused
additional troubles with filters (particularly the multimedia filter if
the URL was a video such as on youtube).
The solution here is similar to what we do in filters. We protect the
whole explicit link so that its content is not further parsed. That
prevents the inner URL to be converted into another link and the
explicit link has the full control.
When H1, H2 and H3 links in wiki act themselves as hyperlinks, they
were displayed in double brackets. This patch removes [[ and ]] out of
the table of content displayed header hyperlinks.
When a section name ended with a URL, the '<a' part of [edit] link
that is appended to the section was considered as part of the URL
in the section, thus causing the [edit] link to be broken.