Widget Customizer: Use ?wp_customize=on.

Let _wp_customize_include() handle customizer initialisation.
Sets also the priority for the Add Widget and Reorder buttons and removes debug cruft.

props westonruter.
fixes #27291.
Built from https://develop.svn.wordpress.org/trunk@27524


git-svn-id: http://core.svn.wordpress.org/trunk@27367 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/js/customize-widgets.js

@@ -1132,6 +1132,7 @@ var WidgetCustomizer = ( function ($) {
 
 			params = {};
 			params.action = self.update_widget_ajax_action;
+			params.wp_customize = 'on';
 			params[self.update_widget_nonce_post_key] = self.update_widget_nonce_value;
 
 			data = $.param( params );
@@ -1153,7 +1154,6 @@ var WidgetCustomizer = ( function ($) {
 			}
 			data += '&' + widget_content.find( '~ :input' ).serialize();
 
-			window.console && window.console.log( wp.ajax.settings.url, data );
 			jqxhr = $.post( wp.ajax.settings.url, data, function ( r ) {
 				var message,
 					sanitized_form,