Update helper.php

Prevents thousands separator (",") from being used when total cache size exceeds 1mb.

http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=31826
Remove unused language strings in com_weblinks
Remove unused language strings in com_contact
Fix system tests for language changes.
Fix problem with select fields not in view.
[#31753] PGSQL Missing #__ prefix on CONSTRAINT "uc_ItemnameTagid" in installation/sql/postgresql/joomla.sql.
[#31894] Check for context in vote plugin
[#31749] JModuleHelper::isEnabled always returns true.
Fix regression in vote plugin caused by [31894].
 + [#31850] The parent item search ajax based on menu location. Thanks
Lu Nguyen
(Fix #1827)
 # [#31890] tagged items list has class "list-striped" and
"list-condensed" in code. Thanks Elin waring.
(Fix #1865)
Merge pull request #1942 from brianteeman/patch-13

Remove unused language strings in com_contact
 $ Updating Italian Tinymce lang file
Fix some PHPCS issues
Correction
[#31998] Smart Search Index Button broken
 # [#31987] *Joomla multilingual install: sef and flags issues. Thanks
Beat
(Fix #1965)
 $ [#31942] Two factor authentication - Language file. Thanks Brian
Teeman
(Fix #
 # [#31985] Remove clear lines at the TinyMCE. Thanks Tobias Zulauf
(Fix #1964)
 # [#31817] *Helpsites.xml Refresh button not active in front-end
profile edit. Thanks Julien Vonthron
(Fix #1959)