Style nit
Add preliminary support for .mbtiles

We still have the limitation of having to create a project using the
TileMill UI. But that will be solved soon...
Generate the KML using Jinja templates

More readable. At the beginning I decided not to use Jinja because
our use case was too simple and sounded overkill, but now it will
be needed for the TileMill project files.
Generate .mbtiles!

Yeah, now --tiles generates .mbtiles using TileMill which is way
faster then gda2tiles.py. The generated file is ready to be uploaded
as a Mapbox layer or can be used in a self-hosted tile server.
Add convenience option for uploading the maps to the cloud

Will upload to a server configured at ~/.tilemill/config.json
Updated docs and renamed the tile script name