Expose http.ClientRequest and http.ServerResponse

lib/http.js

@@ -314,6 +314,7 @@ function ServerResponse () {
   this.use_chunked_encoding_by_default = true;
 }
 process.inherits(ServerResponse, OutgoingMessage);
+exports.ServerResponse = ServerResponse;
 
 ServerResponse.prototype.sendHeader = function (statusCode, headers) {
   var reason = STATUS_CODES[statusCode] || "unknown";
@@ -336,6 +337,7 @@ function ClientRequest (method, uri, headers) {
   this.sendHeaderLines(method + " " + uri + " HTTP/1.0\r\n", headers);
 }
 process.inherits(ClientRequest, OutgoingMessage);
+exports.ClientRequest = ClientRequest;
 
 ClientRequest.prototype.finish = function (responseListener) {
   this.addListener("response", responseListener);