alpha3, admin1_abbr, datafix for leading *

this PR contains 3 pieces of work:

- add `alpha3` property to `admin0` `admin1` `admin2` and `localadmin` [1] [2]
- add `admin1_abbr` property, add mapping file to extract USA state abbreviations
- fix a long standing bug where some quattroshapes names have a leading `*` for no reason

[1] http://en.wikipedia.org/wiki/ISO_3166-1_alpha-3
[2] https://github.com/foursquare/quattroshapes/issues/5