Always handle errors from Satan.executeRemote()
Propagate usage.lookup errors in getMonitorData()
Add an err param to launchDaemon callback, require daemon to be launched as root in OSX
Update satan.mocha.js test to include new launchDaemon err param
Remove old message about node-usage not working on Mac OS

But sanity check that monit object is attached to processes and it does
not include an error property