Fix #167

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Do not use System.err to dump Google Closure errors and warnings.

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Fix #153

Add documentation about authentication and content negotiation

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>