refactored mp_tree.MP_NodeQuerySet.delete() to avoid an extra argument.
refactored mp_tree.MP_NodeQuerySet.delete() to avoid an extra argument.

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