Add annotations property (Map of string/string) to all Configuration Resources

[Hampapur Ajay]

It is desirable to have a generic key-value pair(string to string) dictionary on every
Configuration Resource/Object. This can be used by clients (like orchestration plugins etc.) to store information in objects that are not 'core' to Contrail.

Some use-cases for this include:
1. to support annotations as defined in Kubernetes
2. passing configuration (or otherwise) parameters to third party services launched/used for
   loadbalancing etc.

The presence of this property (to be defined as a MapProperty) is optional on a resource.

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/24419
Submitter: Hampapur Ajay (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/24419
Committed: http://github.org/Juniper/contrail-controller/commit/f7316c769449449eaaaea93f4cec9de02d86aa25
Submitter: Zuul
Branch: master

commit f7316c769449449eaaaea93f4cec9de02d86aa25
Author: Hampapur Ajay <email address hidden>
Date: Fri Sep 23 14:57:59 2016 -0700

Add support for a MapProperty called 'annotations' on all resources.

Change-Id: I69ce5792997b101a98e062e4afb77061e5f21933
Closes-Bug: 1627201