Add compatibility for 0.9 / 0.10 Streams

Fall back to readable-stream 0.2.0 for older
versions of Node. Also update tests now that
callling end() after end() does not throw.

package.json

@@ -25,7 +25,7 @@
   },
   "dependencies": {
     "over": "~0.0.5",
-    "readable-stream": "0.0.3",
+    "readable-stream": "~0.2.0",
     "setimmediate": "~1.0.1"
   }
 }

pullstream.js

@@ -4,9 +4,13 @@ module.exports = PullStream;
 
 require("setimmediate");
 var inherits = require("util").inherits;
-var PassThrough = require('readable-stream/passthrough');
+var PassThrough = require('stream').PassThrough;
 var over = require('over');
 
+if (!PassThrough) {
+  PassThrough = require('readable-stream/passthrough');
+}
+
 function PullStream(opts) {
   var self = this;
   this.opts = opts || {};

test/pullStreamTest.js

@@ -260,8 +260,8 @@ module.exports = {
     });
   },
 
-  "throw on calling data or end after end": function (t) {
-    t.expect(2);
+  "throw on calling write() after end": function (t) {
+    t.expect(1);
     var ps = new PullStream({ lowWaterMark : 0 });
     ps.end();
 
@@ -272,13 +272,6 @@ module.exports = {
       t.ok(ex);
     }
 
-    try {
-      ps.end(new Buffer('hello', 'utf8'));
-      t.fail("should throw error");
-    } catch (ex) {
-      t.ok(ex);
-    }
-
     t.done();
   },