[2.1.0] Implement MakeAbsolute URI filter

- Move some directives with complex dependencies to URIDefinition
- Fix a missing extends
- Add hierarchical information to URI schemes
- Fix bug in URIHarness.

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1346 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/URIScheme.php

@@ -19,6 +19,12 @@ class HTMLPurifier_URIScheme
      */
     var $browsable = false;
     
+    /**
+     * Whether or not the URI always uses <hier_part>, resolves edge cases
+     * with making relative URIs absolute
+     */
+    var $hierarchical = false;
+    
     /**
      * Validates the components of a URI
      * @note This implementation should be called by children if they define