Use Daemon to authenticate task instead of scheduler.username and scheduler.password

TRUNK-3781 gives modules the ability to run tasks as the Daemon user without having to authenticate manually and store a user account with the scheduler.username and scheduler.password global properties.

This will be back-ported to 1.7.5 and 1.8.5. Once that is complete, this module should be updated to require 1.7.5 and use the Daemon class