Move all middleware into middleware module.

[hswolff]

This PR moves all middleware functions that were previously in core/server.js into core/server/middleware.js.

This was done to improve the readability of core/server.js and to centralize all middleware functionality to one module.

Aside from moving the functions, they were modified to use the express application instance attached to the ghost singleton: ghost.server.

[ErisDS]

The main reason for moving middleware to middleware.js was to make it possible to write unit tests for them. I'd rather only move each function as and when it gets unit tests - unless you're happy to add them?

[hswolff]

Happy to do so! Will get on it as soon as possible.

[hswolff]

I've started working on creating tests for every middleware that I'm moving. All are going well except I've hit a snag and I'm not sure how to test middleware's that use the api module directly.

For example the redirectToSignup

Ghost/core/server.js

Line 72 in c2ab917

function redirectToSignup(req, res, next) {

. Any help on how to best add a test case for that middleware?

I'm halfway through the middleware, should have them done soon.

[hswolff]

So I think I got as far as I could with this. I didn't move any middleware functions that I wasn't sure how to create tests for.

@ErisDS let me know if there's any revisions this may need. Thanks!