Theme install: Set a timeout and error message for API responses.

props ocean90.
fixes #27708.

Built from https://develop.svn.wordpress.org/trunk@28105


git-svn-id: http://core.svn.wordpress.org/trunk@27936 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/js/theme.js

@@ -325,6 +325,7 @@ themes.Collection = Backbone.Collection.extend({
 		return $.ajax({
 			url: 'https://api.wordpress.org/themes/info/1.1/?callback=?',
 			dataType: 'jsonp',
+			timeout: 15000, // 15 seconds
 
 			// Request data
 			data: {

wp-admin/theme-install.php

@@ -56,7 +56,7 @@ wp_localize_script( 'theme', '_wpThemeSettings', array(
 		'searchPlaceholder' => __( 'Search themes...' ), // placeholder (no ellipsis)
 		'upload' => __( 'Upload Theme' ),
 		'back'   => __( 'Back' ),
-		'error'  => ( 'There was a problem trying to load the themes. Please, try again.' ), // @todo improve
+		'error'  => sprintf( __( 'An unexpected error occurred and we can&#8127;t reach WordPress.org. If you continue to have problems, please try the <a href="%s">support forums</a>.' ), __( 'https://wordpress.org/support/' ) )
 	),
 	'installedThemes' => array_keys( $installed_themes ),
 	'browse' => array(