Support using new-style dynamic drivers

Ironic is implementing a new way to define and use drivers. Instead of monolithic drivers with hardcoded interfaces (e.g. pxe_ipmitool), we'll have hardware types that define compatibility with interfaces. Users will be able to pick a hardware type and an implementation for each interface (or just leave the default). E.g. you can set driver to just "ipmi" and then pick a deploy procedure ('iscsi" or "direct") or console implementation ("no-console", "shellinabox", "socat"). See http://specs.openstack.org/openstack/ironic-specs/specs/approved/driver-composition-reform.html for details.

Anticipated TripleO changes:
* Update puppet-ironic to support new configuration options (enabled_hardware_type, enable_*_interfaces, default_*_interface).
* Update puppet-tripleo to include ironic::drivers::interfaces for easy configuration.
* Make tripleo-common understand new driver names and new fields.
* Enable default set of hardware types (presumably, IPMI, Drac and iLO) both in under- and overcloud.
* Make "inspector" the default inspection implementation in the undercloud.
* Enable "socat" console implementation both in under- and overcloud to be able to use nova serial console with bare metal nodes.
* Switch CI (or parts of it) to using hardware types.