[Tagging] Open Defecation Areas Add disused or abandoned

[Warin]

One important thought.

Past open defecation areas will need to remain mapped... but not as 
areas in use.

I think these are clearly life cycle tags .. but

disused does not appeal as it is unlikely that it could be used again 
until quite some time has past (pun sorry)

abandoned might be better. 'abandoned:open_defecation_area=yes'???

Thoughts?