Move app.yaml to app.yaml.template and add app.yaml to svn:ignore in trunk/app. Each Google App Engine instance needs its own "application:" ID, and this should *not* be committed into the SoC SVN repository in trunk/app. (Individual deployment branches *will* have app.yaml files with Google App Engine application IDs in them, just not trunk/app.)

class BaseCreation(object):
    """
    This class encapsulates all backend-specific differences that pertain to
    database *creation*, such as the column types to use for particular Django
    Fields.
    """
    pass