Change tokenizer constant references to self::

Changing static:: to self:: makes constant de-referencing a
compile-time operation rather than run-time, potentially improving
performance. As constants cannot be overridden by extending classes,
there is no advantage to using static:: for these constants

tests/html5lib-tests

@@ -0,0 +1 @@
+Subproject commit 515dc09aaa25d48a72f0d4c1a890507022b36e09