Add draft of d3.chart presentation
Make room for new examples
Begin bullet example... ugh
Prevent accidental state sharing
Generalize original chart ever-so-slightly
Get d3.chart version kind of working
Almost there...
Complete initial d3.chart implementation

Still to do: clean up old code. Create a higher-order container chart
using the `mixin` API.
Remove unused code
PARTIAL: Begin implementing higher-order chart
Complete bullet chart example
Re-name files as appropriate
Add content