use display_name instead of private chef
All omnibus-ctl to be invoked without having the service management
commands.

Addons (e.g. pushy/reporting/manage) don't manage their own services
but use the private-chef-ctl runit.

This patch allows for a second initialization option 'service_commands'
(true by default to mimic current behaviour) where the ctl command does
not have any runit related commands
service-list is only enabled when we have service commands
Merge branch 'jc/OC-10621/no-services-for-addons'
Merge branch 'remove-private-chef-reference' of github.com:smith/omnibus-ctl into smith-remove-private-chef-reference
Merge branch 'smith-remove-private-chef-reference'