Tests query string extraction.

URL: http://webkit.org
Query: null

URL: http://webkit.org?foo
Query: foo

URL: http://webkit.org#bar
Query: null

URL: http://webkit.org?foo#bar
Query: foo

URL: http://webkit.org?foo=bar?baz
Query: foo=bar?baz

URL: http://webkit.org?foo?bar#baz
Query: foo?bar