New HiDPI spinner. Uses clean <span class="spinner"></span> markup.

Be on the lookout for weirdness.
props lessbloat. see #21456.



git-svn-id: https://develop.svn.wordpress.org/trunk@22019 602fd350-edb4-49c9-b593-d223f7449a82

wp-admin/includes/template.php

@@ -360,7 +360,7 @@ function wp_comment_reply($position = '1', $checkbox = false, $mode = 'single',
 	<span id="savebtn" style="display:none;"><?php _e('Update Comment'); ?></span>
 	<span id="replybtn" style="display:none;"><?php _e('Submit Reply'); ?></span></a>
 	<a href="#comments-form" class="cancel button-secondary alignleft"><?php _e('Cancel'); ?></a>
-	<img class="waiting" style="display:none;" src="<?php echo esc_url( admin_url( 'images/wpspin_light.gif' ) ); ?>" alt="" />
+	<span class="waiting spinner"></span>
 	<span class="error" style="display:none;"></span>
 	<br class="clear" />
 	</p>