Take a path to a field like "yacms.pages.models.Page.feature_image"
    and return a model key, which is a tuple of the form ('pages', 'page'),
    and a field name, e.g. "feature_image".

def parse_field_path(field_path):
    """
    Take a path to a field like "yacms.pages.models.Page.feature_image"
    and return a model key, which is a tuple of the form ('pages', 'page'),
    and a field name, e.g. "feature_image".
    """
    model_path, field_name = field_path.rsplit(".", 1)
    app_name, model_name = model_path.split('.models.')
    _, app_label = app_name.rsplit('.', 1)
    return (app_label, model_name.lower()), field_name