layer ordering from project.yml is not used

[Jesse Crocker]

One of my styles use a layer ordering set in project.yml, instead of the layer ordering from the vector tile source. This works fine in tilemill2, and in Kosmtik, but tilelive-tmstyle seems to ignore the layer ordering from the style and always use the ordering from the source.

Im working on a fix for this and will probably submit a pull request today or tomorrow.