Fix typo in verify_file_md5() description. see [25541].

props siobhan.
see #27651.
Built from https://develop.svn.wordpress.org/trunk@27938


git-svn-id: http://core.svn.wordpress.org/trunk@27768 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Clarify tooltips on Edit Image screen.

props siobhan.
fixes #27651.
Built from https://develop.svn.wordpress.org/trunk@27939


git-svn-id: http://core.svn.wordpress.org/trunk@27769 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Theme Installer: Center spinner, remove plural string.

fixes #27581. see #27055.

Built from https://develop.svn.wordpress.org/trunk@27940


git-svn-id: http://core.svn.wordpress.org/trunk@27770 1a063a9b-81f0-0310-95a4-ce76da25c4cd