[1.7.0] Refactor HTMLModule unit tests

- AttrCollections does not barf when an inclusion is not present
- HTMLDefinition configuration directives now use new syntax
- Added %HTML.AllowedModules and %HTML.CoreModules for testing
- Extend Harness so that it can accept a default configuration object member variable
- Refactor modules to use Scaffolding, which defines some custom attributes that allows for the easy testing of attribute collections

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1082 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/AttrCollections.php

@@ -63,6 +63,7 @@ class HTMLPurifier_AttrCollections
             if (isset($seen[$merge[$i]])) continue;
             $seen[$merge[$i]] = true;
             // foreach attribute of the inclusion, copy it over
+            if (!isset($this->info[$merge[$i]])) continue;
             foreach ($this->info[$merge[$i]] as $key => $value) {
                 if (isset($attr[$key])) continue; // also catches more inclusions
                 $attr[$key] = $value;