Connect & Express middleware framework

1. Connect and Express Middleware is the foundation of the program
2. Middleware is a JavaScript function object, contains three parameters (the request object, the response object, next callback function)
3. Connect the Dispatcher dispatcher program and a set of intermediate composition, the next action of intermediate parameters: returns control to the dispatcher.
4. Use use () method of combining intermediate, use () function returns the Connect program example, chain supporting method.