Adds UI for media modal toolbars, buttons, and the selected item(s) status.

Currently uses actions for inserting media into a post as an example (hence the raw text). To test a workflow that supports multiple selection, run the following in your browser's JavaScript console:

	wp.media({ multiple: true });

see #21390, #21808.



git-svn-id: https://develop.svn.wordpress.org/trunk@21769 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/media.php

@@ -1649,5 +1649,16 @@ function wp_print_media_templates( $attachment ) {
 		</div>
 		<div class="describe"></div>
 	</script>
+
+	<script type="text/html" id="tmpl-media-selection-preview">
+		<div class="selected-img selected-count-<%- count %>">
+			<% if ( thumbnail ) { %>
+				<img src="<%- thumbnail %>" />
+			<% } %>
+
+			<span class="count"><%- count %></span>
+		</div>
+		<a class="clear-selection" href="#"><?php _e('Clear selection'); ?></a>
+	</script>
 	<?php
 }