[XMLHttpRequest.open()](https://developer.mozilla.org/en/XMLHttpRequest#open(\)) optionally accepts parameters user and password, so I purpose we allow these properties on the details object that GM_xmlhttpRequest accepts, and if they exist then use them in the XMLHttpRequest.open() call.
[XMLHttpRequest.open()](https://developer.mozilla.org/en/XMLHttpRequest#open(\)) optionally accepts parameters
userandpassword, so I purpose we allow these properties on the details object that GM_xmlhttpRequest accepts, and if they exist then use them in the XMLHttpRequest.open() call.