Applying aleh.fl's patch to forms.py
Applying aleh.fl's patch to forms.py

"""Found bug in my tree-admin implementation.
If you edit some root node, the node itself is not excluded from 'Relative to:'
drop-down, so it is possible to
submit bad parent node id."""

--HG--
branch : admin-aleh

albedoweb/django-treebeard,Ernsting/django-treebeard,velfimov/django-treebeard,velfimov/django-treebeard,velfimov/django-treebeard,kazmiruk/django-treebeard,velfimov/django-treebeard,torchbox/django-treebeard,kazmiruk/django-treebeard,albedoweb/django-treebeard,albedoweb/django-treebeard,torchbox/django-treebeard,kazmiruk/django-treebeard,torchbox/django-treebeard,kazmiruk/django-treebeard,Ernsting/django-treebeard,Ernsting/django-treebeard,albedoweb/django-treebeard