[Imports] GNS tag cleanup

[Paul Norman]

About 6 years ago, a set of data was imported from GNS, consisting of place
names, mainly of place=town.

As an example, see http://www.openstreetmap.org/node/52556192/history

Thy have a few tags, many of which can probably be safely automatically
eliminated by editor software.

Using the example node, I think the following should be added to the
automatic removal list in editors


gns:dms_lat=490200
gns:dms_long=-1224900
gns:lat=49.033333
gns:long=-122.816667
gns:n:xx:full_name=White Rock
gns:n:xx:full_name_nd=White Rock
gns:n:xx:modify_date=1993-12-14
gns:n:xx:sort_name=WHITEROCK
gns:cc1=CA

I'm not sure on the following. Anyone know their history, and if they're of
any use to OSM?

gns:adm1=02
gns:dsg=PPL
gns:fc=P
gns:jog=NM10-08
gns:mgrs=10UEV1340031177
gns:n:xx:nt=N
gns:rc=1
gns:ufi=-575923
gns:uni=-812858


Any comments?