Release 2.0.0

Inclusion of new Projection API (a breaking change from Salt 1.x), which permits projecting from one source record to multiple viz-space coordinates. This enables more complex tiling, such as tiling lines, as well as a more natural expression of zoom (which no longer needs to be built-in as a concept).

Inclusion of SpreadingFunctions, which allows the user to project a single source record into multiple viz-space points and then spread the single value from the source record over those points in a dynamic way.

Improved documentation.