restapi: Trusted Compute Pools - Open Attestation integration with oVirt engine proposal

Detailed description: http://wiki.ovirt.org/Trusted_compute_pools

In this patchset, add RESTful API to create a trusted Cluster.

Change-Id: Ib345054072e4998346c7be6d815d5ea8f3eace4e
Signed-off-by: Jimmy <gang.wei@intel.com>
Signed-off-by: Zhang Lijuan <lijuan.zhang@intel.com>
Signed-off-by: Dave Chen <wei.d.chen@intel.com>
Signed-off-by: Quan Xu <quan.xu@intel.com>