[Node] Updating stream interfaces and removing redundant interfaces.

We duplicated the EventEmitter and Stream interfaces in the "event" module, so I removed the redundant interface definitions.

I have updated the ReadableStream/WritableStream interfaces in accordance with the current documentation:
http://nodejs.org/api/stream.html

I added class definitions for Writable/Transform/Duplex/PassThrough in 'event'. These classes are described in the following Node documentation:
http://nodejs.org/api/stream.html#stream_api_for_stream_implementors

As a result of these changes, I needed to slightly alter other typings to refer to the new interface name. This was unavoidable; I had to rename the `EventEmitter` interface to `NodeEventEmitter` to avoid clashing with the `events.EventEmitter` class that implements `NodeEventEmitter`.

browserify/browserify.d.ts

@@ -5,7 +5,7 @@
 
 /// <reference path="../node/node.d.ts" />
 
-interface BrowserifyObject extends EventEmitter {
+interface BrowserifyObject extends NodeEventEmitter {
 	add(file: string): BrowserifyObject;
 	require(file: string, opts?: {
 		expose: string;
@@ -31,6 +31,6 @@ declare module "browserify" {
 		entries?: string[];
 		noParse?: string[];
 	}): BrowserifyObject;
-	
+
 	export = browserify;
 }