Add TODO comments to remove max_length when Django 1.7 support is dropped

src/oscar/apps/catalogue/reviews/abstract_models.py

     name = models.CharField(
         pgettext_lazy(u"Anonymous reviewer name", u"Name"),
         max_length=255, blank=True)
+    # TODO Remove the max_length kwarg when support for Django 1.7 is dropped
     email = models.EmailField(_("Email"), max_length=75, blank=True)
     homepage = models.URLField(_("URL"), blank=True)
 

src/oscar/apps/customer/abstract_models.py

     user = models.ForeignKey(AUTH_USER_MODEL, db_index=True, blank=True,
                              null=True, related_name="alerts",
                              verbose_name=_('User'))
+    # TODO Remove the max_length kwarg when support for Django 1.7 is dropped
     email = models.EmailField(_("Email"), db_index=True, blank=True,
                               max_length=75)
 

src/oscar/apps/order/abstract_models.py

 
     # Use this field to indicate that an order is on hold / awaiting payment
     status = models.CharField(_("Status"), max_length=100, blank=True)
+    # TODO Remove the max_length kwarg when support for Django 1.7 is dropped
     guest_email = models.EmailField(_("Guest email address"), max_length=75,
                                     blank=True)