Phabricator not set up to use HTTP for Diffusion-hosted repositories

[dillongrove]

There are a few additional steps needed for working with repos over HTTP, which should perhaps we added to the scripts (maybe as a config option?). Without these steps, attempting to clone via HTTP (after doing step 1) results in a confusing 500 error.

1. The diffusion.allow-http-auth option in config must be set to true. I set this within the Phabricator Config UI, but I assume this can be done from the command line as well.
2. An additional line must be added to /etc/sudoers file to give the www-data user access to the necessary git binaries.

www-data ALL=(phabricator-daemon) SETENV: NOPASSWD: /usr/bin/git, /usr/lib/git-core/git-http-backend