detect nodes with unneded highway=crossing

[mkoniecz]

Detection would be very similar to ​http://josm.openstreetmap.de/ticket/9141 - but with "node that may be left by foo in at least two directions" replaced by "node that may be left by foo in at least one direction" (crossing terminating footway/cycleway sometimes happen, also some people may stop mapping feature at this point).

And main check would be:

" Any node with ((without foot access AND without bicycle access) OR (without road) AND (with highway=crossing OR with crossing=no) should be reported as "highway=crossing or crossing=no is probably not needed here"."