Instead of grouping together every control parameter into a single array and passing them all to the JS, use subclasses with custom parameters to implement additional PHP functionality and the parameter to send only the necessary variables to the JavaScript control.
Replaces WP_Customize_Control->control_params with WP_Customize_Control->json and WP_Customize_Control->to_json(). The to_json() method refreshes the json array passed to the JavaScript control (set to control.param by default).
Creates WP_Customize_Upload_Control and WP_Customize_Image_Control.
git-svn-id: http://svn.automattic.com/wordpress/trunk@20319 1a063a9b-81f0-0310-95a4-ce76da25c4cd
wp.Uploader is a wrapper that provides a simple way to upload an attachment (using the wp_ajax_upload_attachment handler). It is intentionally decoupled from the UI. When an upload succeeds, it will receive the attachment information (id, url, meta, etc) as a JSON response. If the upload fails, the wrapper handles both WordPress and plupload errors through a single handler.
As todos, we should add drag classes for the uploader dropzone and account for the rough 100mb filesize limit in most browsers. The UI for the customizer upload controls could be improved as well.
git-svn-id: http://svn.automattic.com/wordpress/trunk@20179 1a063a9b-81f0-0310-95a4-ce76da25c4cd
