[dev] Authenticate with an remote HTTP authentication

[Chuck Hagenbuch]

Quoting Duck <duck at obala.net>:

> Attached is a new authentication driver that uses HTTP_Request to login to an
> remote HTTP basic authentication system. My case is to login users against a
> remote svn/apache server and users passwords are store in remote password
> file.

Added, along with usage of the global proxy configuration. Thanks!

-chuck