This adds a new parameter to ft_backlinks() to ignore permissions which
is needed for invalidating the cache of linking pages with useheading
enabled. This also adds various test cases for ft_backlinks().

The resize token was broken because fetch.php cleans the id before the token calculation, while ml() uses the raw id

ensure security token is included in media url when resize parameter is passed in string form, e.g. 'w=80'

When pages contain non-UTF8 chars (eg. when posted through a script or
when edited on the filesystem, parts of DokuWiki can break resulting in
missing page content. This fixes these problems by forcing the content
to UTF-8 on load. This will result in bad characters for input that is
not latin1 but contents will at least be visible.

FS#2415 add  to mediamanager (refactor pageinfo() and shift MEDIAMANAGER_STARTED after mediainfo() sets up )

There is a condition inside idfilter() function that helps Apache on Windows to properly handle colon as a namespace separator by replacing it with semicolon. However, this is not necessary on Microsoft IIS server so the condition was improved.

FS#2700)

Note: These changes don't work yet. The cookie is not set and deletes the old
one.

This is untested and probably broken currently

Before this change it was possible to send arbitrary HTML content to
subscribers, if you are using HTML subscription mails and have
untrustworthy editors, it is recommended to upgrade as soon as possible
(this doesn't affect the current stable release).

This readds the last part of the subscription system: the normal "every"
subscriptions.

now the actual sending of bulk messages (digest, list) is reimplemented
and partially tested.

Still not complete