Feature/tilemap

I think TileMap is ready for review. 
There some UI features that I'd like to discuss to enable switching map types and setting/changing some params.

For now, default map type is the quantizeCircleMarkers.
To change map type, see 73 to 76: 
https://github.com/jthomassie/kibana/blob/feature/tilemap/src/kibana/components/vislib/visualizations/tile_map.js#L73-76
I'm getting an error that rows[rows.length - 1] is undefined. You might need to add a check to make sure there is actually a value there for the min. 

![image](https://cloud.githubusercontent.com/assets/41702/4957855/628886bc-66a8-11e4-9ddd-4db144a5213d.png)