Improvements: New service phases, restart on conf chage, new service abstraction

I changed the impl to use the new service crate abstraction in order to avoid a `"hash_echo: command not found"`  that seems to be a bug on `(p.actions/service ... :if-flag "xyz")`.  (see discussions on [IRC](http://www.raynes.me/logs/irc.freenode.net/pallet/2013-06-21.txt))

Please do review the new service stuff 'cause I'm not 100% confident I "got it". It seems to work fine here.
I should add tests to cover this :-\