Update style_themes.lang.php
Update themes.php

Updated existing name check and error placing for New, Edit, Duplicate.
Update themes.php
Update themes.php
Update themes.php
Fixes #1109 Duplicate Theme Name Fix
Used existing language variable
Updated narrations.
Initial commits

Deal with https://github.com/mybb/mybb/issues/1169
Fixes #1208 xmlhttp.php theme loading doesn't make any sense
Fixes #1232 - autocomplete not translatable

Fixes https://github.com/mybb/mybb/issues/1232
Fixes #1273 Moderator Tools - No permission
Merge remote-tracking branch 'upstream/feature' into fix-1208
Added check for cookied theme, whether no theme was loaded and the CDN check.
Also moved a wrong comment in global.php
Fixes #1256 : Updating user posts breaks postbit

1. Fixing post pid which was wrong.
2. Invalid code chunk removed. What is the logic behind checking "If not isset" inside "If isset" of the same thing?
Fixes #1270 sequrity question

Fixes error text for sequrity question not wrapping.
Fix #1188

https://github.com/mybb/mybb/issues/1188 images not scaled
Remove max-height scaling

As it's not really needed and hard to fix.
fix: Warning time error, refs #1283

* warnings.php
  * expires_period was accessed as numeric value, but is a string
* inc/datahandlers/warnings.php
  * improved handling of expiry for custom warning reasons
* inc/languages/english/datahandler_warnings.lang.php
  * added error message for invalid expires_period
Remove unnecessary height

...