Make parsing of Google Maps URIs more flexible

When opening a location in certain apps (like WhatsApp) the value of q
in the called URI is something like "loc:xx.xxxxxxx,x.xxxxxxx (Du) ".
Until now extract() expects "xx.xxxxxxx,x.xxxxxxx" as input and cannot
parse URIs like the one above.

Solve this problem by cutting off unnessessary peaces of the URI.
Merge pull request #469 from Bewahn/master

Make parsing of Google Maps URIs more flexible