Customizer: Fix header image cropping when working with huge images. Affected Firefox in particular.

props ehg.
fixes #27790.

Built from https://develop.svn.wordpress.org/trunk@28101


git-svn-id: http://core.svn.wordpress.org/trunk@27932 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Custom header: Fix image ordering.

props ehg.
see #21785. fixes #27791.

Built from https://develop.svn.wordpress.org/trunk@28102


git-svn-id: http://core.svn.wordpress.org/trunk@27933 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Don't auto-resize Quick Draft textarea in IE < 9. Avoids IE8 crash.

props morganestes.
fixes #27761.

Built from https://develop.svn.wordpress.org/trunk@28103


git-svn-id: http://core.svn.wordpress.org/trunk@27934 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Themes screen: Fix RTL layout issue in Firefox.

props SergeyBiryukov.
fixes #27779.

Built from https://develop.svn.wordpress.org/trunk@28104


git-svn-id: http://core.svn.wordpress.org/trunk@27935 1a063a9b-81f0-0310-95a4-ce76da25c4cd