strip_tags_long: use htmlpurifier to properly reformat html content

lib/htmlpurifier/library/HTMLPurifier/ConfigSchema/schema/HTML.SafeEmbed.txt

@@ -0,0 +1,14 @@
+HTML.SafeEmbed
+TYPE: bool
+VERSION: 3.1.1
+DEFAULT: false
+--DESCRIPTION--
+<p>
+    Whether or not to permit embed tags in documents, with a number of extra
+    security features added to prevent script execution. This is similar to
+    what websites like MySpace do to embed tags. Embed is a proprietary
+    element and will cause your website to stop validating. You probably want
+    to enable this with %HTML.SafeObject.
+    <strong>Highly experimental.</strong>
+</p>
+--# vim: et sw=4 sts=4