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.
Fixes #1208 xmlhttp.php theme loading doesn't make any sense
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
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.
Remove unnecessary height

...
Fixes #1294 Custom Mod Tools not updating properly
Merge pull request #1119 from demonate/patch-6

Fixes #1109 Themes with same name
Preparing 1.8.0 release
Fixes #700 - invalid HTML

https://github.com/mybb/mybb/issues/700
Merge pull request #1295 from PaulBender/fix-1294

Fixes #1294 Custom Mod Tools not updating properly
Merge pull request #1209 from JN-Jones/fix-1208

Fixes #1208 xmlhttp.php theme loading doesn't make any sense