Allow updates req.form to accept multiple values for the same attribute (i.e multiple html options select element)

Hello, it seems when sending a request containing more than one result for the same attribute, only one is caught by req.form.

"body":"fn_1=&fn_0=&org=sdsd&title=&tel=&email=&url=&adr_street=&adr_city=&adr_zip=&adr_country=¬e=&categories=Advisory+Board&categories=Secretariat&categories=Partner",
"peer":"127.0.0.1",
"form":

{ "org":"sdsd", "categories":"Partner", "kind":"org" }

,

as you can see categories has 3 different values `categories=Advisory+Board&categories=Secretariat&categories=Partner` but only the last one prevails. It is easy to understand why this happens, but it would be very helpful to perhaps generate and array with all the values when this happens.