new stager reverse_http_proxy_pstore

This does the same as windows stager reverse_http but it also tries to obtain authentication from Windows Protected Storage (used in Win XP and Win Server 2003, IE Version 4 to 6) and passes them to the preconfigured proxy server via InternetConnect function.

If no authentication is found or there is no preconfigured proxy server, this should work just like reverse_http.
Is it expected of me to do this? I don't really know the code structure of MSF and don't even know where to put this new mixin.