Toyplot 0.8.0

• Removed deprecated colormap and palette parameters from the API.
• Allow simplified color mapping specifications.
• Improved test coverage.
• Fix a problem embedding embedding axes in tables using more than one merged cell.
• Add table cell width / height support for real-world units.
• Hide masked values in table axes.
• Reorganize the installation documentation.
• Add support for rotated text in table cells.
• Add top/bottom/left/right label support for matrix visualizations.
• Add new toyplot.locator.Null do-nothing tick locator.
• Add matrix visualization support for right / bottom ticks.
• Add custom locator support for matrix visualizations.
• Make matrix visualization color parameters consistent with the rest of the API.
• Add missing reference documentation for toyplot.projection module.
• Cleanup the toyplot.color.broadcast(...) API and implementation.
• Make the API for specifying color mapping consistent across all visualization types.
• Allow per-datum titles on line plots and scatterplots.
• Expand the color section in the user guide to cover color mapping.
• Add a new section on null data to the user guide.
• Eliminate nuisance warnings from numpy.
• Automatically validate source notebooks as part of the documentation build.