fix #9157 - add opening_hours validation test

This test utilizes https://github.com/ypid/opening_hours.js which is licensed
under the New (2-clause) BSD license.



git-svn-id: http://josm.openstreetmap.de/svn/trunk@6370 0c6e7542-c601-0410-84e7-c038aed88b3b