Adds "pause" and "resume" events to pump and it's readable argument.

lib/sys.js

@@ -284,14 +284,25 @@ exports.exec = function () {
 
 
 exports.pump = function (readStream, writeStream, callback) {
+  if (!readStream.pause) readStream.pause = function () {readStream.emit("pause")};
+  if (!readStream.resume) readStream.resume = function () {readStream.emit("resume")};
+
   readStream.addListener("data", function (chunk) {
     if (writeStream.write(chunk) === false) readStream.pause();
   });
 
+  writeStream.addListener("pause", function () {
+    readStream.pause();
+  });
+
   writeStream.addListener("drain", function () {
     readStream.resume();
   });
 
+  writeStream.addListener("resume", function () {
+    readStream.resume();
+  });
+
   readStream.addListener("end", function () {
     writeStream.end();
   });