Upgrade to Express 4.x

[raymondfeng]

/to @ritch @bajtos

[bajtos]

AFAIK loopback should not include middleware modules in its dependencies, so that the app does not have to install middleware it does not need. That's to point of using a safe require in the wrapper object, right?

[raymondfeng]

Most of them are required by LoopBack for runtime and testing. I think we need to flush out the template for scaffolded app.js first. There might be opportunities to remove or move the deps to dev/optional sections after that.

[bajtos]

This is the minimal app.js that works:

var app = loopback();
app.use(loopback.rest());
app.listen(3000);

IMO loopback should bundle only middleware required to make the example above work, plus any middleware required by loopback custom middleware like loopback.token.

Modules required by loopback tests should be declared as dev dependencies.

[bajtos]

I would not worry about the app.js scaffolded by loopback-workspace, loopback-workspace can scaffold the appropriate dependency entries in package.json.

[bajtos]

lib/express-wrapper.js is not longer a wrapper. Please rename to something more appropriate, e.g. lib/express-middlewares.js.

[bajtos]

LGTM.