Revert [21495]. Discussed in dev-chat: it's better if the themes implement this or something similar. 

git-svn-id: http://core.svn.wordpress.org/trunk@21532 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Twelve: add flexible-header tag back into style.css, in anticipation of it being a core-allowed tag, see #21065.

Remove responsive-width since it's not decided yet, see #21065.


git-svn-id: http://core.svn.wordpress.org/trunk@21533 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix typo in [21529], props toscho. Simplify the :focus styles for the Screen Options and Help toggles, see #21324

git-svn-id: http://core.svn.wordpress.org/trunk@21534 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Compress scripts/styles: 3.5-alpha-21535.

git-svn-id: http://core.svn.wordpress.org/trunk@21535 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Disable the Link Manager on any future upgrade if it is still enabled but there are no links. see #21307.



git-svn-id: http://core.svn.wordpress.org/trunk@21536 1a063a9b-81f0-0310-95a4-ce76da25c4cd
If the DB upgrade hasn't yet been run, assume the Link Manager is disabled. Important for multisite installs. props ryan. see #21307.



git-svn-id: http://core.svn.wordpress.org/trunk@21537 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Send Content-Type with charset for iframe_header(). Props SergeyBiryukov, sergey.s.betke@novgaro.ru. fixes #19454

git-svn-id: http://core.svn.wordpress.org/trunk@21538 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Output a hidden input of blog_charset when we are hiding the option. props SergeyBiryukov. see #21507.



git-svn-id: http://core.svn.wordpress.org/trunk@21539 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Twelve: minor CSS cleanup for extra trailing selector comma, spacing, and too-specific class selector.


git-svn-id: http://core.svn.wordpress.org/trunk@21540 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Introduce wp_get_mime_types() for fetching the complete list of mime types. Remove the static caching of the types so that filters other than the first filter work. Use wp_get_mime_types() in do_enclose(). fixes #21299 #21594

git-svn-id: http://core.svn.wordpress.org/trunk@21541 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Twelve: output dynamic end comment ID value for navigation container (above|below).


git-svn-id: http://core.svn.wordpress.org/trunk@21542 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Twelve: remove twentytwelve_is_categorized_site() in favor of a theme-agnostic future core fix for this issue, see #21479.

Also simplify the logic for checking tag and categories, props SergeyBiryukov and obenland.


git-svn-id: http://core.svn.wordpress.org/trunk@21543 1a063a9b-81f0-0310-95a4-ce76da25c4cd
We no longer need to check function_exists() for date_default_timezone_set(). props Gary-J, j-idris. fixes #20501.



git-svn-id: http://core.svn.wordpress.org/trunk@21544 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Update TinyMCE to 3.5.6, see #21173

git-svn-id: http://core.svn.wordpress.org/trunk@21545 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Compress scripts/styles: 3.5-alpha-21546. TinyMCE updated.

git-svn-id: http://core.svn.wordpress.org/trunk@21546 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix the display of widgets in wp-admin when their descriptions wrap to two lines. props mattdanner. fixes #15180

git-svn-id: http://core.svn.wordpress.org/trunk@21547 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Compress scripts/styles: 3.5-alpha-21548.

git-svn-id: http://core.svn.wordpress.org/trunk@21548 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix screen reader text in IE7 and 8 in the toolbar "Updates" menu, props SergeyBiryukov, fixes #21333

git-svn-id: http://core.svn.wordpress.org/trunk@21549 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Always return a variable reference from get_pages(). props wonderboymusic, foxinni. fixes #20756.



git-svn-id: http://core.svn.wordpress.org/trunk@21550 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Remove unused multisite option 'language'. props wonderboymusic. fixes #21545.



git-svn-id: http://core.svn.wordpress.org/trunk@21551 1a063a9b-81f0-0310-95a4-ce76da25c4cd