MDL-16348 Reorganise admin tree:

* New Capability report put under Users -> Permissions
* Miscellaneous category renamed to Development
* Unit tests and Functional DB test moved to be under Development.
* The hard-coded hack that was used to change the permission that controls the Backups and stats reports replaced with settings.php files.
* There were two hidden Miscellaneous things in the old category, so I moved them. Multilan upgrade now under Lanuages, and Online assignment cleanup now under Plugins -> Activity modules. Both still hidden.

There was already a way for admin report plugins to control where they appeared in the tree, but it was not documented, so see http://docs.moodle.org/en/Development:Admin_reports

admin/settings/plugins.php

@@ -33,6 +33,8 @@ if ($hassiteconfig) {
         }
     }
 
+    // hidden script for converting journals to online assignments (or something like that) linked from elsewhere
+    $ADMIN->add('modsettings', new admin_externalpage('oacleanup', 'Online Assignment Cleanup', $CFG->wwwroot.'/'.$CFG->admin.'/oacleanup.php', 'moodle/site:config', true));
 
     $ADMIN->add('modules', new admin_category('blocksettings', get_string('blocks')));
     $ADMIN->add('blocksettings', new admin_page_manageblocks());