Histogram is now rendered properly and has frequency labels above every bar.
Added a vertical line (red) indicating the performance target (3 days).
Added links to each prison.
Display another line for the 95-th percentile.
Added d3.chart.bubble-matrix
No comment.
Bubble matrix now displays when visits are processed.
Added a graph for when visits are requested.
Changed tick labels on histograms to say N days.
Slight cleanup of DetailedMetrics.