Problems Using Proto3 Timestamps

[mcos]

For the record, I'm using protobuf v3.0.0, php 5.6 and the composer requirement for this library is

"require": {
        "stanley-cheung/protobuf-php": "^0.6.0"
    },

When I use the timestamp well-known type from protobuf3, like so:

import 'google/protobuf/timestamp.proto';

message Foo {
  google.protobuf.Timestamp bar = 1;
}

The messages are generated asphp with the following syntax:

/**
     * Get <bar> value
     *
     * @return \google\protobuf\Timestamp
     */
    public function getBar(){
      return $this->_get(6);
    }

    /**
     * Set <bar> value
     *
     * @param \google\protobuf\Timestamp $value
     * @return \Foo
     */
    public function setBar(\google\protobuf\Timestamp $value){
      return $this->_set(6, $value);
    }

The issue I have is that there's no way for me to import the \google\protobuf\Timestamp value into my namespace, as it isn't generated, so I can't actually call setBar(), above.

Is there guidance for using the new well-known types in a particular way? Also, is there support for json serialization of these types?