This was a relic of an older attempt to display a tooltip per color for the hover node.
It worked, but was pretty unwieldy.

Renamed shape categories to `linear` and `hspline` and made `linear` the default.

Added colorscale mock

(property isn't wired up properly yet)

More consistent with other traces, and now it's possible to display
only probabilities, only counts, both, none (with hover effects),
or skip (not hover effects).

There are three arrangement modes:
 - `perpendicular` (default): categories only drag vertically,
    dimension labels drag horizontally.
 - `freeform`: category labels can drag vertically and horizontally
    (in which case they pull the dimension along with them). Here
    dragging a category can reorder the categories and dimensions.
 - `fixed`: dragging of dimensions and categories is disabled.

Not working yet, just a checkpoint

Mocks updated, but not tests yet.

…els` construct

to the control font of dimension labels and category labels respectively

Makes the hoverlabel shifting logic more noticeable and shows off
the `counts` attribute

Now there are tests for 'freeform', 'perpendicular', and 'fixed'
arrangements for dragging the dimension label and category rectangle.

for better consistency with other trace / axis types.

…attributes

Get mouse x position relative to graph div rather than relative to page

This combines the former colorbar and font mocks. And adds a parcats
trace with a Latex category label as well.