Escape story fields and clean story HTML with HTML Purifier.

Add HTML Purifier 4.19.1. Stories are purified when they are saved and
when they are shown.

lib/htmlpurifier-4.19.1/library/HTMLPurifier/ConfigSchema/schema/Attr.AllowedClasses.txt

@@ -0,0 +1,8 @@
+Attr.AllowedClasses
+TYPE: lookup/null
+VERSION: 4.0.0
+DEFAULT: null
+--DESCRIPTION--
+List of allowed class values in the class attribute. By default, this is null,
+which means all classes are allowed.
+--# vim: et sw=4 sts=4