Use the core https module instead of request.

Added bonus: GitHub responses are now compressed, and we can relay the
compressed response directly to the client instead of recompressing it.
Set a timeout for GitHub requests.
Always decompress GitHub responses for now.

Nginx doesn't seem to like getting compressed responses.
Add Vagrant config.

Install Vagrant and run `vagrant up` to boot a Vagrant box running
rawgithub fronted by Nginx.
Merge branch 'vagrant'
Merge branch 'master' into http
Disable HTTP connection pooling.
Fix If-None-Match support once and for all (I hope). Fixes #13