title: Django admin- inlines and collapse fields
body: <p>I am using inlines to allow the editing of the Drivers and Riders objects from Family in the admin, as shown below.  I would like the Driver and Rider objects to be collapsed, but it appears that that only works for fields in the class, not fields coming from an inline.  Is there a way to collapse  Rider and Driver as listed below?</p>
  
  <p>Thanks!</p>
  
  <pre><code>class LegAdmin(admin.ModelAdmin):
      list_display = ('drive_date', 'start_time', 'endpoint')
  
  class DriverInline(admin.StackedInline):
      model = Driver
      extra = 0
  
  class RiderInline(admin.StackedInline):
      model = Rider
      extra = 0
  
  class FamilyAdmin(admin.ModelAdmin):
      inlines = [DriverInline, RiderInline]
  
  
  
  #admin.site.register(Driver)
  #admin.site.register(Member)
  #admin.site.register(Rider)
  admin.site.register(Leg, LegAdmin)
  # admin.site.register(DriveDay)
  admin.site.register(Carpool)
  admin.site.register(Family, FamilyAdmin)
  admin.site.register(DrivingPreference)
  </code></pre>