Geom.bar rendering. Faster zoom/pan.
Finish reimplementing bar geometry.
Reimplement Geom.boxplot
Reimplement Guide.title
Update Geom.label.
Update Geom.ribbon.
Update Geom.errorbar.
Reimplement continuous color keys.
Fix some continuous color key issues.
Update Geom.hexbin.
Adapt to polygon and lines changes in Compose.
Update Geom.hline, Geom.vline.