Change path-user and path-group to return names
Allow configuration of pallet state directory

The directory used to store md5 and and backup files on the node can
be configured via the :state-root key of the admin user.
User specific upload path for local files
Upload via temporary
Add :state-group option to admin user

When uploading files from localhost, state-group will be used to share
ownership of uploaded files between the admin user and the sudo user.

A chgrp will be done, if the upload files do not have the state-group
group ownership.
Assume paths starting with $ are absolute

When calculating the pallet state path, assume paths starting with $
will expand to absolute paths.