ipython/nbviewer — pull request #143 by minrk (2013-12-14 00:55:03+00:00)
Title: Some more logging changes

+ handle more cases in failed upstream fetch
- turn 599 (tornado client errors) into 400, 404, not 502
- turn 4XX in 400, not 500
+ log the proxied IP, not the load-balancer's IP
+ log referer of redirects and errors
+ log user agent of errors
+ log all headers of requests that cause unhandled (500) errors