Allow quotes in cookie values, and don't quote cookie values when sending to the server

I've had this logiic running in my fork for over a year now with no apparent issues. This is the original email I sent to the mailing list about it:

> I've got a site sending a cookie whose value looks like a JSON object, e.g., {"name1":"val 1","name2":"val 2"};
> This violates the cookie specs in many ways, but browsers don't seem to have any problem with it. It looks like > linkchecker is already allowing commas and whitespace in cookie values, so only double-quotes are causing > > parsing issues in this example. 
> 
> If we allow quotes, however, linkchecker escapes them while wrapping the entire value in a pair of double  quotes. I was not able to make the site in question happy until I removed the quoting/escaping logic while sending > cookies. 
> 
> It appears that Firefox does not quote cookie values either. I did not check any other browsers.