patch for utfgrid

[nippo]

Hi,

Is it possible to add grid data to https://github.com/mapbox/mbutil/blob/master/patch?

Thanks!

[nippo]

Hi,

I don't know why but when the tiles are generated with TileMill, we just need to add these requests:

REPLACE INTO keymap SELECT * FROM source.keymap;
REPLACE INTO grid_utfgrid SELECT * FROM source.grid_utfgrid;
REPLACE INTO grid_key SELECT * FROM source.grid_key;

Thanks for your great work!