Send typical proxy headers

[ankon]

It would be nice if the proxy logic would send over some headers to the origin server:

1. HTTP/1.1 usage
2. X-Forwarded-For, X-Forwarded-Proto, X-Forwarded-Port headers, so the origin can understand the original source of the request
3. X-Request-Start so it is possible to track timings of the requests from the beginning

Note that I made the X-headers conditional on a new 'headers' configuration option, mainly because having the X-Forwarded-Proto seems to break origins on AWS cloudfront some reason.

This is on top of #32, although that would not be required.

[hone]

Can you split this from #32 and #30? I'll need to look at some of these headers but it looks good.

[hone]

@jmervine thoughts?

[jmervine]

I love the x- stuff... I'd need to do some more research to comment on the following...

      proxy_http_version 1.1;
      proxy_set_header Upgrade $http_upgrade;
      proxy_set_header Connection "upgrade";
      proxy_set_header Host $proxy_host;

[jmervine]

@rdsharma

[James1x0]

Hi there, it's been a few years... can we please get proxy header support? Please!

[Subtletree]

@hone @schneems would this PR get looked at after a rebase and some added clarity around the extra headers?

[edmorley]

Hi

This buildpack is now deprecated and we are recommending people move the more actively maintained heroku-buildpack-nginx. For migration advice see here.

As such, I'm closing this PR out since we won't be making further changes to this buildpack.