Add support for proxy authentication

[GoogleCodeExporter]

I'm try using this solution into network what has a proxy.
When this happens the error below is displayed.

"---------------------------
Download Error
---------------------------
The remote server returned an error: (407) Proxy Authentication Required.
---------------------------
OK   
---------------------------"

Original issue reported on code.google.com by frchico on 26 Mar 2009 at 3:19

[GoogleCodeExporter]

Original comment by azizatif on 29 Mar 2009 at 12:58

• Changed title: Add support for proxy authentication
• Added labels: Component-Logic, Milestone-Release1.0

[GoogleCodeExporter]

Original comment by azizatif on 9 May 2009 at 11:50

• Changed state: Started