Add file upload protocol
Set the file-uploader from action-options
Add node-state protocols
Allow action-options in environment

Also splits state-root implementation into state-root-checksum and
state-root-backup.
Fix creation of state root and upload dirs
Add rsync file uploader
Add no-op file-checksum and file-backup implementations
Use effective username for sftp upload path
Use effective user in rsync
Update to clj-ssh 0.5.7