[Workbench1] Load configuration from cluster config file
At startup, Workbench should
arvados-server config-dump < /etc/arvados/config.yml(if that fails, error out)
- load the resulting YAML document
- use that document (instead of .../config/application.yml etc) as the application configuration
- Loading the new config at startup
- Changing the config key uses to the new keys
- If .../config/application.yml exists, values there should take precedence. This should be done with the same code used in RailsAPI. "config dump" and "config diff" rake tasks should be provided, just like in RailsAPI.
- Install guide and upgrading/release notes need to be updated to ensure the "arvados-server" package is installed on the workbench host.
- Update Arvbox to install arvados-server.