Removed the _-prefix for populate().

Several parts of Django call get_apps() with a comment along this lines
of "this has the side effect of calling _populate()". I fail to see how
this is better than just calling populate()!

django/core/serializers/base.py

@@ -137,10 +137,9 @@ class Deserializer(six.Iterator):
             self.stream = six.StringIO(stream_or_string)
         else:
             self.stream = stream_or_string
-        # hack to make sure that the models have all been loaded before
-        # deserialization starts (otherwise subclass calls to get_model()
-        # and friends might fail...)
-        app_cache.get_apps()
+        # Make sure the app cache is loaded before deserialization starts
+        # (otherwise subclass calls to get_model() and friends might fail...)
+        app_cache.populate()
 
     def __iter__(self):
         return self

django/core/serializers/python.py

@@ -88,7 +88,8 @@ def Deserializer(object_list, **options):
     db = options.pop('using', DEFAULT_DB_ALIAS)
     ignore = options.pop('ignorenonexistent', False)
 
-    app_cache.get_apps()
+    app_cache.populate()
+
     for d in object_list:
         # Look up the model and starting build a dict of data for it.
         Model = _get_model(d["model"])