Pull Request: 304 and 204 responses should have empty bodies

[Petter Bergman]

Hi Snap Maintainer(s)!

I would like to draw your attention to the issue documented in this PR:

https://github.com/snapframework/snap-server/pull/81

IMO it quite serious, as it makes snap practically unusable if behind a proxy, for example Apache in Reverse Proxy mode. Mobile users of my site in fact reported it as being completely unuseable (mobile operators usually have their own proxy, exascerbating the problem).

Regards

Petter Bergman