Support geospatial queries

Implement spatial query functionality in Drill to provide location based queries and filtering. It could be similar to PostGIS for Postgres and allow queries like:

select * from
(select columns[2] as location, columns[4] as lon, columns[3] as lat,
ST_DWithin(ST_Point(-121.895, 37.339), ST_Point(columns[4], columns[3]), 0.1) as isWithin
from dfs.`default`.`/home/k255/drill/sample-data/CA-cities.csv`
)
where isWithin = true;

Working proposal is available at http://github.com/k255 (see drill-gis and drill fork).