Themes screen: Add aria-describedby attributes to provide better information to screen readers.

props joedolson for initial patch.
fixes #26602 for trunk.


git-svn-id: http://develop.svn.wordpress.org/trunk@27012 602fd350-edb4-49c9-b593-d223f7449a82
Autosave: don't set "submit" buttons to disabled right before submitting the form. They are not sent with the form data, see #25272.


git-svn-id: http://develop.svn.wordpress.org/trunk@27015 602fd350-edb4-49c9-b593-d223f7449a82
Let `is_attachment()` accept an $attachment parameter, similar to `is_page()` and `is_single()`. Adds Unit Tests for all 3.

Props alex-ye for the initial patch.
Fixes #24257.



git-svn-id: http://develop.svn.wordpress.org/trunk@27016 602fd350-edb4-49c9-b593-d223f7449a82
Fix a bit of whitespace from [27016].



git-svn-id: http://develop.svn.wordpress.org/trunk@27017 602fd350-edb4-49c9-b593-d223f7449a82
Fix imperceptible whitespace cruff from [27017].



git-svn-id: http://develop.svn.wordpress.org/trunk@27018 602fd350-edb4-49c9-b593-d223f7449a82
Remove byte order mark (BOM) from GetUrlInContent.php. see #26171.

git-svn-id: http://develop.svn.wordpress.org/trunk@27019 602fd350-edb4-49c9-b593-d223f7449a82
Fix typo in CSS. props ciantic, MikeHansenMe. fixes #26898.

git-svn-id: http://develop.svn.wordpress.org/trunk@27020 602fd350-edb4-49c9-b593-d223f7449a82