Remove redundant socket.io

Client-side Socket.io provided by server.
Load client-side socket.io correctly.

(app.js) Authorize twitter stream with user credentials.
(main.js) Remove top element before appending new.
(views/layout.jade) Load client-side socket.io via: <script
src='/socket.io/socket.io.js'>
TwitterStream.js => twitterAuth.js
cnnbrk-tweets.jade => cnnbrk-stream.jade
(twitterAuth::broadcastTweet) Add per-client filter, streamText[].
Add start.server script

(start.server) Set NODE_PATH and NODE_ENV prior to running app.js
Add twitter layout template and stylesheet.