Basic Auth Base64 endocding

[ximex]

There is a problem with usernames/passwords with special chars like ä,ö,ü.

The problem is this part:
https://github.com/iriscouch/browser-request/blob/master/index.js#L433-L472

If i take the function from the original request lib it works:
https://github.com/request/request/blob/master/lib/helpers.js#L45-L47