Openflow 1.3#4

Hi.

As i had mentioned in the issue#3, there will a error message when we use the "/wm/core/controller/switches/json" REST API to fetch the switches information on the OF1.0. I think that is caused by the serializer which calls a unsupported function. I think the solution is that we create a custom serializer for the result value.

Solution
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1. Create a custom serializer IOFSwitchSerializer for IOFSwitch.
2. Ask the IOFSwitch use tat custom serializer to serialize when it needs.
3. Since the ControllerSwitchesResource is responsible for processing the REST request for "/wm/core/controller/switches/json", I modify its return value to a set of IOFSwitch instead of the original iterator.

Result
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1. It work for OF1.0 and OF1.3
2. I have test the following format and all work.
    -  /wm/core/controller/switches/json
    -  /wm/core/controller/switches/json?dpid=00:00:00:00:00:00:00:01
    -  /wm/core/controller/switches/json?Dpid__StartsWith=00:00

Feel free to give your comments about this problem.

Thanks.