Deprecate shipped 404 and 500 middlewares

[jasisk]

A couple of middleware ship in the kraken-js package but are—otherwise—not configured or enabled by default. They are able to be added to a project that uses kraken-js by being required:

var middlewareFactory = require('kraken-js/middleware.404');
app.use(middlewareFactory('templateName'));

These middleware are presently configured by default with the yeoman generator. However, it's been my experience that they cause more problems than they solve. Some of the problems we've seen involve assumptions based on xhr and not content-type, the assumption a rendering engine exists resulting in 404s turning into 500s, etc. Relying on the default handler that ships with express is sufficient while developing, while writing an appropriate handler for production (404, 5xx) should be standard practice.

[aredridel]

Burn them with fire.

[pvenkatakrishnan]

👍

[jasisk]

Just waiting on dougwilson/nodejs-depd#17.

[jasisk]

Closed by #361