lc.scm (handle-list): Add new argument to the `hosts' command.

* ui/lc.scm (handle-list): Take a host ID passed as an argument
  for `hosts' command as a request for information about the
  specific host.
* ui/cli/pretty-format.scm (format-host): New procedure.
* lazycat-daemon/lazycatd.scm (handle-list-req): Handle requests
  for a host information.
* lazycat-daemon/host.scm (host-serialize/state): New method.