Widgets: on clicking Add, don't move the chooser out of the widget early as that makes is visible at the bottom of the screen. Remove the cloned copy of it instead. Part-props jeremyfelt, fixes #26417.
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git-svn-id: http://core.svn.wordpress.org/trunk@26541 1a063a9b-81f0-0310-95a4-ce76da25c4cd