skeleton of in-depth profiling ideas. refs https://github.com/mapbox/tm2/issues/146
don't leave your dirty laundry on the floor. also don't make variables you don't need.
simple tests for geometry stats
name change to layerinfo, adds featurecount and jsonsize
change semver range to work with node 0.8
dont make em use new
Merge pull request #44 from mapbox/more-stats

Tile Profiling