Re-implemented the six.with_metaclass functionality to avoid having to include six in the distrubution.

src/utils/picklefield.py

@@ -32,6 +32,7 @@ Modified for Evennia by Griatch.
 from copy import deepcopy
 from base64 import b64encode, b64decode
 from zlib import compress, decompress
+#import six # not in default syslib
 import django
 from django.db import models
 
@@ -112,7 +113,11 @@ def _get_subfield_superclass():
     # see https://github.com/django/django/commit/222c73261650201f5ce99e8dd4b1ce0d30a69eb4
     if django.VERSION < (1,3):
         return models.Field
-    return six.with_metaclass(models.SubfieldBase, models.Field)
+    # mimic six.with_metaclass
+    meta = models.SubfieldBase
+    base = models.Field
+    return meta("NewBase", (base,), {})
+    #return six.with_metaclass(models.SubfieldBase, models.Field)
 
 
 class PickledObjectField(_get_subfield_superclass()):