[Tagging] toilets:wheelchair or wheelchair_toilet (Both iD presets)

[Dave F]

Hi

toilets:wheelchair 64875 (iD & wheelmap preset)
wheelchair_toilet 4550 (iD preset)

What does wheelchair_toilet represent that's different from 
toilets:wheelchair?
If there isn't one I think wheelchair_toilet should be removed from iD's 
presets

Other combinations which should potentially be changed:
wheelchair:toilets 467
wheelchair:toilet 10
toilet:wheelchair 6

DaveF