phd - on start command accurately detect if daemons are running before erroring out

Summary: loadRunningDaemons loads daemons that may be running (have a file pid). other commands handle this appropriately so just make sure the start command knows whats up

Test Plan: phd start, stop, reload all seemed to work just fine.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T1284

Differential Revision: https://secure.phabricator.com/D2808