Phase 1 / v1.x release

[springmeyer]

I propose the v1.x release focus exclusively on a common set of headers with enumerations for Mapbox Vector Tile types. See #1 for how this could reduce duplication: e.g. between https://github.com/mapbox/mapnik-vector-tile/blob/master/src/vector_tile_config.hpp and https://github.com/Project-OSRM/osrm-backend/blob/master/include/util/vector_tile.hpp.

Further phases (2.x and 3.x) would focus on adding decoding and encoding support.

[mapsam]

@springmeyer @flippmoke which syntax would you prefer?

constantexpr

const constexpr std::uint32_t LAYER_TAG = 3;

enum

enum Tile_Encoding : std::uint32_t
{
    LAYERS = 3
};

[mapsam]

Either way, how do we want to access the constants? We can be hyper explicit in the namespaces or just have command underscore _ nomenclature.

Explicit namespace

writer.add_uint32(vector_tile::Encoding::Tile::VERSION, 2);

Underscores

writer.add_uint32(vector_tile::VERSION_TAG, 2);

Or something in between?

[springmeyer]

Great work @mapsam, closed by #4