[2.1.2] Implement experimental HTML5 parsing using PH5P

- Fix debugger so that tokens can be printed without an index
- Fix some broken PEAR unit tests

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1383 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/Lexer.php

@@ -189,6 +189,9 @@ class HTMLPurifier_Lexer
                 return new HTMLPurifier_Lexer_DOMLex();
             case 'DirectLex':
                 return new HTMLPurifier_Lexer_DirectLex();
+            case 'PH5P':
+                // experimental Lexer that must be manually included
+                return new HTMLPurifier_Lexer_PH5P();
             default:
                 trigger_error("Cannot instantiate unrecognized Lexer type " . htmlspecialchars($lexer), E_USER_ERROR);
         }