Cast wp_count_attachments() before iterating it to avoid a notice when items exist without a mime type.

props bobbingwide.
fixes #27802.

Built from https://develop.svn.wordpress.org/trunk@28139


git-svn-id: http://core.svn.wordpress.org/trunk@27970 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add missing string translation in widgets.

see #27453, #27112.

Built from https://develop.svn.wordpress.org/trunk@28140


git-svn-id: http://core.svn.wordpress.org/trunk@27971 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Theme Installer: Fixes for browsers without pushState.

props gcorne.
see #27055.

Built from https://develop.svn.wordpress.org/trunk@28141


git-svn-id: http://core.svn.wordpress.org/trunk@27972 1a063a9b-81f0-0310-95a4-ce76da25c4cd
TinyMCE: fix icons in IE7, fixes #27829
Built from https://develop.svn.wordpress.org/trunk@28142


git-svn-id: http://core.svn.wordpress.org/trunk@27973 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Widgets: Remove create_function() from the customizer class.

props westonruter.
fixes #27805.

Built from https://develop.svn.wordpress.org/trunk@28143


git-svn-id: http://core.svn.wordpress.org/trunk@27974 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Graceful failures for TinyMCE views of video/audio playlists.

props gcorne.
fixes #27821.

Built from https://develop.svn.wordpress.org/trunk@28144


git-svn-id: http://core.svn.wordpress.org/trunk@27975 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Translate a string added in 3.7.1 but never translated previously.

props SergeyBiryukov.
fixes #27819.

Built from https://develop.svn.wordpress.org/trunk@28145


git-svn-id: http://core.svn.wordpress.org/trunk@27976 1a063a9b-81f0-0310-95a4-ce76da25c4cd
About page: Use a better preposition to describe drag-and-drop.

see #27713.

Built from https://develop.svn.wordpress.org/trunk@28146


git-svn-id: http://core.svn.wordpress.org/trunk@27977 1a063a9b-81f0-0310-95a4-ce76da25c4cd