Notification of string changes

Author: David Mudrák
MDL-34099 Report available updates for plugins at admin/index.php
The Notifications (admin/index.php) page has now information about
available updates for core and eventually plugins, too. Note that the
structure of the available updates array changed. This breaks backward
compatibility for eventual 3rd renderers out there (not expected
though).


http://git.moodle.org/gw?p=moodle.git;a=commit;h=966bd7852ea70151c8b297e0158ed9c5841ada0d
http://github.com/moodle/moodle/commit/966bd7852ea70151c8b297e0158ed9c5841ada0d

+ 2.4 en [pluginsoverviewsee,core_admin]