Websockets Support And Dual RPC Support

[Rishi556]

This PR adds support for websockets in the JSON RPC. It comes with the following config options:

"rpcWebsockets" : {
        "enabled" : true,
        "port" : 5002
    }

The methods are the same as with HTTP, except there's just one path and it follows the hive style of METHOD_FAMILY.METHOD_NAME, for example:

{ "jsonrpc": "2.0", "method": "contracts.getContract", "params" : {"name" : "tokens"},  "id": 0 }

which would be a call to /contracts with the method getContract. The other METHOD_FAMILY is blockchain for /blockchain requests.

This type of requests can be done via HTTP as well, by providing no path. So the same request from above can be called to /.

[bt-cryptomancer]

Changes look good, will include in next minor version release.