Send attributes of dbus commands with a certain dbus type. 

I found that it was not possible to send dictionary keys with an arbitrary type. For example Boolean, Integer or Float. The only type that is allowed by JSON is string. 

To address this issue I introduced the following keywords, which are related to the DBus Types
dbus.Boolean( value )
dbus.Byte( value )
dbus.Int16( value )
dbus.Int32( value )
dbus.Int64( value )
dbus.UInt16( value )
dbus.UInt32( value )
dbus.UInt64( value )
dbus.Double( value )

A dictionary might now be send like this:

```javascript
var manifest = {
	name: "cloudeebus",
	key: "secret"
};

cloudeebus.log = function(msg) {
  document.getElementById("log").innerHTML += msg + "\n";
}

function errorCB(error) {
  cloudeebus.log("error: " + error + "\n");
}

function logCB(result) {
  cloudeebus.log(JSON.stringify(result));
  cloudeebus.log("tach");
}

function gotBusProxy(proxy) {
  proxy.callMethod("org.genivi.navigationcore.Routing","SetWaypoints", [1,1,0,[{"dbus.UInt16(160)": 53.550880663096905, "dbus.UInt16(161)": 9.993923027068377}, {"dbus.UInt16(160)": 53.56983105652034, "dbus.UInt16(161)": 9.949385952204466}]]).then(logCB, errorCB);
}

function connectSuccess() {
  cloudeebus.SessionBus().getObject("org.genivi.navigationcore.Routing", "/", gotBusProxy, errorCB);
}

cloudeebus.connect("ws://localhost:8080", manifest, connectSuccess, errorCB);
```