WWDC native style compatibility

[mourner]

What needs to be done in llmr to fully support the latest Outdoors style for native (converted with gl-style script):

• @yhahn icon bucket property (e.g. to use maki field for pois) Support using maki as a value for image property mapbox-gl-native#196 — to avoid creating LOTS of poi buckets (one for each poi type). Also see Use token replacement system for icon mapbox-gl-native#300
• @ansis strokeBlur (which will be text-halo-blur) — for some label effects
• @ansis composite blurring: prerender, prerender-size, prerender-blur fill blurring #424 Support polygon blurring mapbox-gl-native#192 — for contour and hillshade blurring
• @yhahn token replacement system ("text-field": '{{name}}' instead of just 'name') mapbox/mapbox-gl-native@c5fd7a0 — for contour labels
• @mourner complex filters (and, or, not, <=, <, etc.) Complex filters in style buckets #430 Complex filters #407
• @mourner 300ms default transition for everything

In addition, there are following issues with rendering Outdoors to be fixed:

• @mourner fix stops function not using closest stop value for zooms after last stop and before first stop
• @mourner translate properties are broken 'translate' properties broken #378
• @mourner rendering order is messed up — some casings render on top of roads
• @mourner pois not appearing at all
• @ansis point-opacity doesn't work for icons
• @ansis some tiles never load Loader.whenLoaded never calls back #402

[ansis]

text-halo-blur added in 5f3b1a9

[mourner]

Fixed stops beyond range.

[mourner]

Tracking minor stuff in separate issues.