Removed daemon support from Sparkplug.

Self-daemonizing services considered harmful. Please use a daemon system more
modern than SysV init; upstart, systemd, daemontools, foreman, and
supervisord all understand non-daemonizing processes well, and they have some
nice process-management properties.

Plus, the daemon-support code never worked well.
Merge pull request #1 from ojacobson/no-daemonize

Removed daemon support from Sparkplug.