While DokuWiki suppresses PHP Notices they are still a code smell and
should be fixed. This fixes some PHP Notices that occurred.

Some of these fixes could be refactored into nicer code once we move to
PHP 7 and get access to the `??` operator.

This allows plugins to easily render a <tfoot> element in a table, even
though it's not used in standard table syntax it makes sense to have it
available.

Let plugins add their own classes to builtin tables or lists.

Fixes #1188
Alternative for #1360 (and PR #1515)

This is required for the filelist plugin to fix issue #11 since $lastlevel became protected in "hrun".

This is a security measurement supported in Chrome and Opera (and
probably other browsers soonish)

See http://mathiasbynens.github.io/rel-noopener/ for rationale

By default, SimplePie sorts RSS entries by the the date on each entry.

If some cases, mostly where RSS is used as a input format for another
service, rendering the order as-is is better than having it sorted.

This patch adds a new parameter for the rss keyword, 'nosort', which can
be used to disable SimplePie's sorting.

This makes it possible to correctly display RSS feeds from "Remember The
Milk", which have a complex order from the system.

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>

- includes, xhtml renderer adding 'node' class to <li> when it contains
  child list(s)

many PHPDocs
some unused variables
some dynamically declared variables declared

Added DOKU_BASE for local target

* allowed urlparams
 * added `wiki:users:` as default user profile link