(url-query url or http-url) -> string or #f
Returns the query field of the given <url> or <http-url>, expressed as a string. (It is stored as a dict.)
Example:
>> testurl :: [http-url #f "www.google.com" 80 ("search") [dict ("client" . "firefox-a") ("ie" . "utf-8") ("oe" . "utf-8") ("q" . "MOSREF Ephemeral Security") >
("rls" . "org.mozilla:en-US:official") ("start" . "0")] #f]
>> (url-query testurl) :: "client=firefox-a&ie=utf-8&oe=utf-8&q=MOSREF Ephemeral Security&rls=org.mozilla:en-US:official&start=0"