Improve http/https outbound request handler probe

[jakewarr8]

trafficstars

I found that a lot of http libs don't use the standard request callback. (superagent , requests).

What do you think about this for http/https outbound?

      // After 'http.request' function returns
      function(target, methodName, methodArgs, probeData, rc) {
        // If no callback has been used then end the metrics after returning from the method instead

        // Need to get request method and URL again
        var ri = getRequestItems(methodArgs[0]);

        if (aspect.findCallbackArg(methodArgs) === undefined) {

          aspect.after(rc._events, ["socket"], probeData, function(target, methodName, methodArgs, context, rc) {
            aspect.before(target._events, ["response"], function(target, methodName, methodArgs, context) {
              that.metricsProbeEnd(probeData, ri.requestMethod, ri.urlRequested, methodArgs[0], ri.headers);
              that.requestProbeEnd(probeData, ri.requestMethod, ri.urlRequested, methodArgs[0], ri.headers);
            });
          });

        }
        return rc;
      }