title: django oscar abstract models customization
body: <p>I want to override django-oscar address application. What I need is to delete some AbstractAddress attributes (apps.address.abstact_models). 
  According to this <a href="http://django-oscar.readthedocs.org/en/latest/howto/how_to_customise_models.html" rel="nofollow">docs</a> the process is following - create local app with the same name and do my magic in models module. Dont forget to import * from default abstract_models in the end of the file. Then add this app into installed_apps and finally schemamigration --auto and migrate.</p>
  
  <p>But django didnt pick up changes. Moreover,
  any attempt to override AbstractAddress class methods are ignored. Why? Is there anything special about abstract_models?</p>