Output a sprite

[samanpwbb]

This project should output a PNG sprite of variable resolution that uses icons from Maki.

[samanpwbb]

if this project took both geojson and a stylesheet as input, this would be straightforward. Such a tool would be especially powerful if multiple sprites were supported in GL (mapbox/mapbox-gl-js#358) because then it'd be possible to overlay full range of icons from maki without dropping or trying to re-write the source style's sprite.

[jfirebaugh]

I think we need to solve mapbox/mapbox-gl-style-spec#220 or otherwise have a way for a style to embed icons directly in the style, with no external references. Otherwise there is no way to actually support the desired usage (new mapboxgl.Map({style: convert(geoJSON)})) because the converted style would have to reference static hosted assets somewhere.