0.21

Support for running multiple neutron-server instances in OpenStack
Support for running neutron-server API workers in OpenStack
Calico Mechanism Driver now performs leader election to control state resynchronization
Extended data model to support multiple security profiles per endpoint
Calico Mechanism Driver now attempts to delete empty etcd directories
Felix no longer leaks memory when etcd directories it watches are deleted
Fix error on port creation where the Mechanism Driver would create, delete, and then recreate the port in etcd
Handle EtcdKeyNotFound from atomic delete methods
Handle etcd cluster ID changes on API actions
Fix ipsets cleanup to correctly iterate through stopping ipsets
Ensure that metadata is not blocked by over-restrictive rules on outbound traffic
Updates and clarifications to documentation