Update en-GB.com_templates.ini

update en-GB.com_templates.ini for #31032

http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=31032
Update categories.php

add delete() function for #31039 (Thanks Julien Celle)

http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_id=8103&tracker_item_id=31039
Merge pull request #1203 from zero-24/patch-14

Update categories.php
Merge pull request #1197 from zero-24/patch-12

Update en-GB.com_templates.ini
Merge remote-tracking branch 'upstream/2.5.x' into 2.5.x-defrules