[1.7.0] Finish implementing legacy elements, begin implementing legacy attributes

- Migrated most unit tests over to XHTML 1.0 Strict to preserve transformation behavior
- Created %Core.ColorKeywords to be shared between CSS_Color and HTML_Color
- Added AttrDef_HTML_Color as AttrType Color
- HTMLPurifier_Config::create(HTMLPurifier_Config $config) now clones the object
- Attribute minimization for HTML implemented in Generator
- Move div@align fix from proprietary to regular set
- Color keywords now map to full six digit hexadecimal codes
- Harness will now tack on per-use-case configuration

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1084 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/Config.php

@@ -70,7 +70,9 @@ class HTMLPurifier_Config
      * @return Configured HTMLPurifier_Config object
      */
     function create($config) {
-        if (is_a($config, 'HTMLPurifier_Config')) return $config;
+        if (is_a($config, 'HTMLPurifier_Config')) {
+            $config = $config->conf; // create a clone
+        }
         $ret = HTMLPurifier_Config::createDefault();
         if (is_string($config)) $ret->loadIni($config);
         elseif (is_array($config)) $ret->loadArray($config);