We now have two CDNs available. code.jquery.com which is the more
popular one and CDNjs which is the faster one. Plugin authors can use a
plugin hook to easily implement their own preferred CDN. Authors might
even use this event to conditionally load additional JavaScript files.

jQuery (and UI and Migrate) are now loaded separately from the rest of
the JavaScript. This adds at least one HTTP request more but has some
advantages:

* browsers can cache it independently
* the cache is only invalidated when versions update
* we do not apply any transformations (replacements, minimizing, etc) on
  this code anymore which makes our dispatcher faster for the other JS
* browsers seem to load (not execut) both (jquery and other) parallel,
  which might increase download speed a bit

This split allowed for the introduction of a new config: jquerycdn. When
enabled the 3 jquery files are loaded from jQueries CDN. This adds
another two HTTP requests but:

* since it's another host those files do not apply to the 4 request per
  host limit and can be loaded (not executed) in paralell which might
  increase download speeds a bit
* the CDN is distributed worldwide which means files are requested from
  the closest location, increasing the download speeds
* since these files/CDN are very popular, chances are high that people
  already have them cached in their browsers, reducing the download time
  to 0 and effectiely halving the javascript needed to download

The option currently defaults to 'off', but I would argue 'on' would be
the better default.

this also removes the non inified versions and incorporates some updates
the jquery CDN just pushed for jquery-ui

jQuery.browser no longer exists in jQuery nor in jQuery migrate. A quick
check in Opera and IE11 suggests that both parts that used it are no
longer needed so they were simply removed.

More browser tests especially for the resize handling in the media manager
are recommended.

The bind() call is deprecated in jQuery 3. This replaces it with
the on() call.

The delegate() call is deprecated in jQuery 3. This replaces it with the
on() call.

jQuery UI replaced the buttonset widget with a controlgroup widget. This
adjusts the JavaScript and styling accordingly.

- jQuery to 3.1.1
- jQuery UI to 1.12.1
- jQuery Migrate to 3.0.0

There are a few warnigs from migrate that have to be fixed. The toggles
in the Media Manager are also missing their proper icons.

Uses paragonie/random_compat instead of insecure home-brewed code.

It's NEVER fine to fall back to mt_rand() for secure random.

Fixes #1760.

Translation update (sr)

Translation update (sr)

inSQL password checking for authpdo

fix calculation of LastRevisionAt

added debug prints to better figure out when LDAP has search issues.

Return valid xml when XML-RPC interface not enabled

Implemented interwiki substitution for external images (issue #1614).

Translation update (zh)

Translation update (sr)

Translation update (no)

currently phpseclib throws an error (about a deprecated function).
errors do not count as failures, so we can't skip them. so for now
7.1 testing is removed again.

DE translation for keys: update_name, update_mail

Usermanager/update lang de

DE translation for key 'protected'

Translation update (ro)