Goal is to make it easy to create an alternate "save" button with a 'form' attribute pointing to that ID, be it in pagetools or anywhere else (related to https://github.com/splitbrain/dokuwiki/issues/764)

- ACL's hand-written template doesn't use div.content to wrap the footnote content
- jQuery object existence check should use $obj.length

Because the isAccessibleByUser method can be run in contexts where $INFO
is not available, an explicit check is needed.

php7 syntax fix.
https://forum.dokuwiki.org/thread/15725
https://forum.dokuwiki.org/post/58606

php7 syntax fix.
https://forum.dokuwiki.org/thread/15725
https://forum.dokuwiki.org/post/58606