Add a paramter to disable deep objects in output

[B4dM4n]

Add the parameter exclude_all_relations to create_api_blueprint, which disables deep object queries when True.
This also disables relations included with include_columns.

[jfinkels]

This needs a test case, and needs to be documented in docs/customizing.rst before I can merge it.

[B4dM4n]

I discontinued using this form of exluding relations, because it doesn't allow to include specific ones.
My solution for now is a simple wrapper like this:

def create_api(manager, model, exclude_relations=False, **kwargs):
  from flask.ext.restless.helpers import get_relations

  if exclude_relations:
    if 'include_columns' in kwargs:
      app.logger.warning('include_columns is set, but exclude_relations is True for %s', model)
    else:
      kwargs.setdefault('exclude_columns', []).extend(get_relations(model))
  manager.create_api(model, **kwargs)