add symbol* properties/keys
merge text and icon buckets/styles

(we're not yet placing together!)
move sprite to a use future loading
better warning messages
fix enum tests
comment out verbose log line
Remove unused
port https://github.com/mapbox/mapbox-gl-js/commit/954dc6591fb6bef812881daf686ab3164d259ea6
port https://github.com/mapbox/mapbox-gl-js/commit/5a9a1b14b94b18277c4495199dc19e0cb96619fc
Remove rounding
allow for CLI-only iOS project building
Avoid libuv resource leaks (fixes #395)
update shaders and backport some collision changes
update symbol placement to be more like js
fix boolean operators
change max_angle_delta to max_angle
port mapbox/mapbox-gl-js#ffd529df107bfec446fa4b4454a583f296c38819
correctly calculate placement depth
make sure to check the promise
don't require the background layer to be named "background"