Provide a more readable host qos api

provide a easier way to pin vcpu
move endpoint from "os-host-servers-qos" to "os-host-qos"

Change-Id: I7c1105947089e1ac5dcc0db3cc90b22aa0d6d826
Limit network inbound/outbound for vm

Limit network inbound/outbound for vm by cgroups

Change-Id: I4f6f88b037ae26fbf7d957a96de51a8b1b4fae18
New api/db resource for tenant qos group

Add tables for tenant_qos_group: "tenant_qos_groups",
"tenant_qos_items","tenant_qos_group_mappings"
Add default tenant qos group with uuid=0
Add api resource "TenantQos"
Add db api for CURD tenant_qos_group

Change-Id: I5a3e334deddded729066dca5fda9dce754504a11
Add exception handler in api and db process

TenantQosGroupIdExists - tenant qos group created failed - HTTPBadRequest
TenantQosGroupNotFound - tenant qos uuid not found in db - HTTPNotFound

Change-Id: Ie15904d086da109e7f46a045ce299ec533d9cd8d
validate the setting values

Change-Id: Ief7479a3b3b199fdf5a49440a8d7a86e69f0dcea
Raise NotImplementedError if driver not support

Raise NotImplementedError if driver not support host qos operations

Change-Id: I6db83960087787559427fcf3049b06ebd4a4794a