[3.1.0] Deprecate addFilter; set up Filter namespace

- Added EXTERNAL dependency config-schema value
- Fix safe bug in Printer_HTMLDefinition
- Fixed broken smoketests

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1669 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/ConfigSchema/InterchangeBuilder.php

@@ -120,6 +120,10 @@ class HTMLPurifier_ConfigSchema_InterchangeBuilder
             $directive->deprecatedVersion = $hash->offsetGet('DEPRECATED-VERSION');
         }
         
+        if (isset($hash['EXTERNAL'])) {
+            $directive->external = preg_split('/\s*,\s*/', trim($hash->offsetGet('EXTERNAL')));
+        }
+        
         $interchange->addDirective($directive);
     }