[1.6.x] Replaced "not PY3" by "PY2", new in six 1.4.0.

Conflicts:
	django/db/backends/oracle/base.py
	django/db/backends/sqlite3/base.py
	django/db/models/base.py

Backport of 365c3e8b from master.

django/template/loaders/app_directories.py

@@ -15,7 +15,7 @@ from django.utils.importlib import import_module
 from django.utils import six
 
 # At compile time, cache the directories to search.
-if not six.PY3:
+if six.PY2:
     fs_encoding = sys.getfilesystemencoding() or sys.getdefaultencoding()
 app_template_dirs = []
 for app in settings.INSTALLED_APPS:
@@ -25,7 +25,7 @@ for app in settings.INSTALLED_APPS:
         raise ImproperlyConfigured('ImportError %s: %s' % (app, e.args[0]))
     template_dir = os.path.join(os.path.dirname(mod.__file__), 'templates')
     if os.path.isdir(template_dir):
-        if not six.PY3:
+        if six.PY2:
             template_dir = template_dir.decode(fs_encoding)
         app_template_dirs.append(template_dir)
 

django/template/loaders/eggs.py

@@ -27,7 +27,7 @@ class Loader(BaseLoader):
                     resource = resource_string(app, pkg_name)
                 except Exception:
                     continue
-                if not six.PY3:
+                if six.PY2:
                     resource = resource.decode(settings.FILE_CHARSET)
                 return (resource, 'egg:%s:%s' % (app, pkg_name))
         raise TemplateDoesNotExist(template_name)