add abbreviation support, aka fallback text label (S.F. versus San Francisco)

[nvkelso]

From the FortiusOne work, bring back the ability to abbreviate features based on array of fallback columns.

For country labels:

United States of America
United States
U.S.A.
U.S.
US

San Francisco
San Fran.
S.F.
SF

[nvkelso]

Looks for name column

--name-columns name1column,name2column,name3column
--name-columns "name1column, name2column, name3column"

with default remaining

--name-columns "name"