Optional --s argument

[perrefe]

Hi,

I want to use this java http server as a custom "default-http-backend" for a kubernetes ingress, but it is not possible to satisfy this requirement:

• Serve a 404 page at /

GreenLightning is started with a required argument that specifies the default landing page, so it ends there.

In addition, it will be nice if GreenLightning do a redirect to 404.html, 500.html, 403.html, etc.. static pages according to the http error code at response.

[nathantippy]

Great, that is good feedback. Right now I am working on rest support. Once that is done I will start on these.