Attach XML/Object Utils to Models

[damonkelley]

There are a number of utilities or "presentation" functions, that would be much more at home attached to a model.

For example, coda_replication.presentation.xmlToQueueEntry would be more appropriate as a converter constructor on the QueueEntry model...

class QueueEntry(models.Model):
# ...
    @classmethod
    def from_xml(self, xml):
         # xmlToQueueEntry body here.

Of course, not all of the functions will work like this. An xml -> object function that just updates an object might be more appropriately attached as an instance method.