Return 404 if compute node not found

Return 404 if compute node not found

Change-Id: I26c0b3ed0144e3bb85bdcf75a9c9215210b6d6f4
Clean unused reference in tenant_qos

The HostAPI is not used, remove it from init

Change-Id: I215314853b8ec76875b6759a36b1fed7c5e93a26
Api to get vm diagnostics in one hypervisor

Change-Id: I992031d9badf067a0ce0e9489f95014ec7dcb659
Endpoint: ../os-hypervisors/{hypervisor_id}/os-hypervisor-diagnostics
Method: GET
Enhance Tenant QoS API

1.Add API to get default qos settings
2.Add API to unassign a project from a qos group(add it to default group)

Change-Id: Id776ac9ebf9bf8cf74d1e37ca80e3746399b791f
Tenant Diagnostics Enhancement

Get tenant diagnostics info by getting all instance in the tenant
diagnostics host by host.

Change-Id: Icbe5f661254151cca3dc12d85929f54b1e32054f