Only try to set a new basetype object if there is a rest_path. Patch to
avoid a superfluous grep and some warnings.
Well, ooops. Sometimes it's not a new node, but a new basetype we want
to create.
Move things from base.tx to basetype.tx where they belong. Also, have a
basetype form even when there's no current_basetype - for adding a new.
Add a new object when no basetype is found. This to make sure we can
crate a new from the form.