#4567 URLs incorrectly parsed in comments

URL parsing in comments doesn't recognize " as a valid part of the url so inserts the domain name in the middle of a url. An example would be a google search query that uses quotes:

http://www.google.ca/search?hl=en&q=foo+"foo+bar"

This shows up as
http://www.google.ca/search?hl=en&q=foo+ [google.ca]"foo+bar"

Note that while " can be encoded as %22, it is a valid url character unencoded.