Drive paint attribute binding logic off the style spec

[jfirebaugh]

I'd like to see declarations like this replaced with:

paintProperties: ['circle-color', 'circle-radius', 'circle-blur', 'circle-opacity']

And ideally, even the list of data-driven properties would itself be derived from the style spec.

The logic for how to bind a paint property to an attribute or uniform can be driven by style specification properties, and dependent not on the individual property but on its type. All color properties are bound the same way. Numeric properties with a spec-defined minimum and maximum can derive an integer size and multiplier from that range. Numeric properties where the minimum or maximum value is not defined should probably just use a float attribute, to avoid issues like #3464.