Refactored genesis:start/stop/restart tasks

Advantage of DRY code, and documented tasks (shows up in cap -T)
Implemented documented logs tasks:

* genesis:logs:apache:access (tail relevant access logs)
* genesis:logs:apache:error (tail relevant error logs)
* genesis:logs:varnish (invoke varnishlog binary)
* genesis:logs:pound (tail+grep syslog)