fuzzy image comparison + create diff images
add links to compare urls
allow specifying a maximum allowed difference in the info json
replace {{token}} with {token}, and %d/%d/%d with {z}/{x}/{y}

refs https://github.com/mapbox/mapbox-gl-style-spec/pull/87
switch to GeoJSON-style geometry type names

refs https://github.com/mapbox/mapbox-gl-style-spec/pull/69
move render type to layer top level

refs https://github.com/mapbox/mapbox-gl-style-spec/issues/80
update fixtures
prettify output
fix other style as well
fix invalid json
Merge branch 'master' into access_token

Conflicts:
	src/map/source.cpp
read access token from environment
read access token from environment