Add emacs indent info for on-one-node
Add execute-and-flag-metadata to pallet.api

Produces a map that when applied to a phase will ensure the phase
is executed only once.
Fix error detection in flag-and-execute
Make update of /etc/hosts optional in set-hostname

If DNS is set up, we may not want to configure /etc/hosts on hostname
changes.
Allow scripts to set interpreter arguments

When using the exec action, passing a sequence to :interpreter-args
will result in these flags being used with the interpreter to invoke
the script.
Add language to temp file extension for scripts

Some interpreters require a specific extension.