fix for issue 112: cuke4duke-maven-plugin is does not use username/password for proxy connection

[imod]

This pull request fixes issue 112: #112

this is a killer issue for us, would it be possible to pull this request?

thanks domi

[joelbyrnes]

I'd like to +1 this request. This is also an issue for my team. I wrote essentially the same fix then found this one. Please pull it in :)

Note this may not be a fix in all cases - the maven docs state that the user/pass could be stored in a secure keystore (as they can be with repo auth) in a future release. I don't know if this is the case yet, I didn't check. In that case, the username may not be available simply by calling activeProxy.getUsername().
http://maven.apache.org/guides/mini/guide-proxies.html

But it's still an improvement from no auth :)