Fix "Directions" link

Examples:
(without this fix)
http://maps.google.com/maps?f=d&q=7502+East+83rd+Street,+Tulsa,+OK+74133,+USA redirects to https://www.google.com/maps/preview?f=d&q=7502+East+83rd+Street,+Tulsa,+OK+74133,+USA which then redirects to https://www.google.com/maps/dir///@36.2928559,-95.8048779,12z/data=!3m1!4b1!4m3!4m2!1m0!1m0

(with this fix)
http://maps.google.com/maps?q=7502+East+83rd+Street,+Tulsa,+OK+74133,+USA redirects to https://www.google.com/maps/preview?q=7502+East+83rd+Street,+Tulsa,+OK+74133,+USA and works as intended
Merge pull request #25 from cliffordp/patch-1

Fix "Directions" link