GB: 18/8/2012 Checked and uploaded Campbell Island. Note wrapped elevation in if statement to check for value > 0.
HB: 20/8/2012 Updated tags to deal with display=1,2,3 for boulder,small,large and approved for other offshore islands.


RP: i think we should create natural=rock_outcrop, use ele= for the height, adn copy the other two direct with a 'LINZ:' prefix
HB: any use in passing through the "display" field? [yes, see key below]
geological=outcrop ? http://wiki.openstreetmap.org/wiki/Tag:geological%3Doutcrop
natural=stone seems as if for erratics, not bedrock. http://wiki.openstreetmap.org/wiki/Tag:natural%3Dstone
Note we use natural=bare_rock elsewhere, so probably don't double up on that.
display attribute key:
1 a boulder
2 a small rock outcrop
3 a large outcrop