title: access parent form's cleaned_data from inline form clean()
body: <p>I have a main form that has an inline-form. Is it possible to access the main form's cleaned_data from the inline-form's clean function?</p>
  
  <p>Here is why I am asking.</p>
  
  <p>The main form has a field to define if a property is for-sale or to lease. The inline form then displays either a sale price field or fields for the lease amount and deposit. I am trying to validate that if the property is for sale, then the lease and deposit fields should be empty.</p>
  
  <p>I can do this in a view for the frontend interface, but is it possible to be done in forms.py for both the frontend and the admin?</p>