Bz1163338 <oo-install> - Improve command detection and error handling

 - Bug 1163338 <oo-install> - Improve command detection and error handling
- https://bugzilla.redhat.com/show_bug.cgi?id=1163338
  - explicity search /sbin and /usr/sbin when looking for utilities
  - improve error handling around confirm_access

- <oo-install> always set conf_node_external_eth_dev for origin