Make sure the first revision is seen as coming from emptiness, so it can be restored.

props adamsilverstein. fixes #23898.

git-svn-id: http://core.svn.wordpress.org/trunk@23872 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Sanity checks on image metadata to avoid warnings, etc.

fixes #23733. props wonderboymusic.

git-svn-id: http://core.svn.wordpress.org/trunk@23873 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Since post format meta for images now takes an attachment ID only, make sure we label it appropriately and don't do things like esc_url() the value. fixes #23900.


git-svn-id: http://core.svn.wordpress.org/trunk@23874 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Compress scripts/styles: 3.6-alpha-23875.

git-svn-id: http://core.svn.wordpress.org/trunk@23875 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Chat post format code cleanup.

see #23625. props obenland.

git-svn-id: http://core.svn.wordpress.org/trunk@23876 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Thirteen: update Chat post format styles to match markup changes in r23876. See #23869.

git-svn-id: http://core.svn.wordpress.org/trunk@23877 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Use correct escaping function. see #23900.

git-svn-id: http://core.svn.wordpress.org/trunk@23878 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Consistently show "Customize" item in the admin menu. props ethitter. fixes #21413.

git-svn-id: http://core.svn.wordpress.org/trunk@23879 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Avoid PHP notice on blank chat lines. props SergeyBiryukov. see #23625

git-svn-id: http://core.svn.wordpress.org/trunk@23880 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Logged out warnings: by default, load only in the admin. Plugins and themes can load on the front-end when needed, see #23295

git-svn-id: http://core.svn.wordpress.org/trunk@23881 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Heartbeat: improve setting the errorstate, add ajaxurl to the settings object when loading on the front-end, some code cleanup, see #23216

git-svn-id: http://core.svn.wordpress.org/trunk@23882 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Compress scripts/styles: 3.6-alpha-23883.

git-svn-id: http://core.svn.wordpress.org/trunk@23883 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Preserve alpha in WP_Image_Editor_GD when images are not resized.

Props joehoyle
see #23039


git-svn-id: http://core.svn.wordpress.org/trunk@23884 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Merge remote-tracking branch 'upstream/master'