Removes whitespace.
Adds new properties to SC.Request instances: allowCredentials (default true, which will indicate that credentials be included for cross-domain requests (e.g. xhr.withCredentials = true) and isSameDomain (readonly computed property, true if the protocol, domain and port match exactly).

These new properties can be used by an SC.Response subclass to include allowing credentials for cross domain requests. Includes unit tests.
Adds support for setting the `withCredentials` property of the XHR request to true when the request is across domains and the request object permits it (via allowCredentials, which is true by default). This allows CORS requests to include cookies, whereas they otherwise would not. Includes unit tests.