URLs containing colons aren't detected properly #7

Example: a Wikimedia URL such as http://en.wikipedia.org/wiki/File:Hanyu_trad_simp.svg is linked as http://en.wikipedia.org/wiki/File:Hanyu_trad_simp.svg.

According to RFC3986, a colon is a valid character in segments, query strings and fragments: http://tools.ietf.org/html/rfc3986#section-3.3