Fix bug involving autoclose and inline elements in strict <blockquote>.

The newest autoclose code uses the elements property in whether or not an
element should be closed by a particular tag.  The heuristic is simple; if
the element doesn't allow that tag as a child, it closes the parent
container.  This doesn't work, however, with <blockquote>, which while not
allowing inline styles under Strict doctypes, requires them to be passed
through MakeWellFormed.

The fix was to transition MakeWellFormed to call a method to retrieve the
elements, and then have StrictBlockquote implement a special version of
this method.  Future versions of HTML Purifier may be more flexible in this
regard--further study of the HTML5 specification is required.

Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>

library/HTMLPurifier/ChildDef.php

@@ -24,6 +24,14 @@ abstract class HTMLPurifier_ChildDef
      */
     public $elements = array();
     
+    /**
+     * Get lookup of tag names that should not close this element automatically.
+     * All other elements will do so.
+     */
+    public function getNonAutoCloseElements($config) {
+        return $this->elements;
+    }
+    
     /**
      * Validates nodes according to definition and returns modification.
      *