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
Simplify tooltip
Remove unused language strings in com_weblinks
Fix small issue with mod_menu (backend)
Remove unused language strings in com_contact
[#31955] Two factor authentication is broken in the back-end (Fix #1939)
[#31950] Hathor: twofactorauth (user manager) (Fix #1935)
Small typo correction to en-GB.com_ajax.ini
change to the contraction of it is

to keep George happy
Fix up some doc blocks due to phpdoc output missing
Add missing doc blocks or descriptions based on phpDocumentor error report
 # [#31961] *Login Modules wrongly display tips (RTL and LTR)
(Fix #1948)
 $ [#31923] Replace non-existent word multilanguage. Thanks Brian Teeman
(Fix #1901)
monolingual missing
Merge pull request #1947 from brianteeman/patch-15

Small typo correction to en-GB.com_ajax.ini
Merge pull request #1926 from brianteeman/patch-1

Simplify tooltip
 # [#31181] Overflow of text into other column.
 $ [#31944] Standardise on select not check. Thanks Brian Teeman
(Fix #1927)
 # [#31840] Can not set class to calendar input. Thanks Achal Aggarwal
 # [#31929] mod_footer : year do not convert to other calendar like
persian language that use hijri date. Thanks Mohammad Hasani Eghtedar
and Carsten Wirtz
(Fix #1905)