This adds a "*" option to --email-domain to disable email validation, and this renames `--google-apps-domain` to `--email-domain` for clarity across providers

This is accomplished by encoding the access_token in the auth cookie and
unpacking it as the X-Forwarded-Access-Token header for upstream requests.

Can now listen for HTTP clients on unix sockets (and any other Go-supported stream oriented network - see golang.org/pkg/net/#Listen).  Default behaviour is unchanged, any http-address without a scheme is given the default of tcp.

Amended the README so that the usage output is up to date.

The Google Developers Console has a new interface and workflow. Updated the **OAuth Configuration** section with the correct steps, including a few notes on potential missteps.

add travis badge

fix markdown syntax