Rewrote the flyTo implementation to more closely match GL JS’s implementation and the paper on which it is based. Rewrote CameraOptions documentation. Only document units for generic types like double. The semantics of LatLng and Duration are already baked into the types; one just needs to look up the types’ definitions. Also, the […) is set notation, so the braces are supposed to be mismatched. Fixes #3296.