<oo-install>Support for gear profiles/districts

- Add restart_services to configure steps for a host
- add post_deploy step for broker/nodes
- Initial support for setting gear_profile
- add support for valid gear sizes and district mappings
- Run host dns configuration every time installer is run
- make URLs configurable based on version
- Prompt for district/node questions when adding the node role to an
  existing host.
- only ask district/node questions if context is :ose
- Set ose-2.1 as the default for the ose context
- update for github raw URL change