Constant phases (#567)

* Get rid of getPhases

This added a fair bit of complexity, and notable made the Phase classes
dynamically generated.

However, by doing this, we no longer include "process the
token using the rules for" phases in the debug log.

Co-authored-by: Sam Sneddon <me@gsnedders.com>

html5lib/_utils.py

@@ -145,15 +145,3 @@ def moduleFactory(baseModule, *args, **kwargs):
             return mod
 
     return moduleFactory
-
-
-def memoize(func):
-    cache = {}
-
-    def wrapped(*args, **kwargs):
-        key = (tuple(args), tuple(kwargs.items()))
-        if key not in cache:
-            cache[key] = func(*args, **kwargs)
-        return cache[key]
-
-    return wrapped