[20180921222709] Native Agent and Bug Fixes

[ddollar]

Switches to native ECS DAEMON scheduling for agent services.

You will need to re-promote any applications containing an agent service after upgrading to this release.

• #2946 support entrypoint parameter through to aws [@ddollar]
• #2949 fix poorly escaped start output [@ddollar]
• #2950 use ecs daemon services for agents [@ddollar]