This is the original planned improvements to Chart::PNGgraph.  Given the
move away from PNGgraph to GD::Graph, none of these will be implemented
in PNGgraph.  Feel free to petition Martien to include them in GD::Graph.

  -- Steve Bonds

Add TrueType support to all font operations.
Increase the number of examples in the POD documentation
Add legend support to pie graphs. (Idea from Greg Stewart)
Fix bar chart problem aligning zero axis when all values are 
    zero. (Lew Teck Kheng)
Add custom color support to PNGgraph::colors (Rhys from prizegolf)
Create a way to allow one to query the GD coordinates of an area on 
    the chart.  [Probably going to be a major overhaul.]  (abbott)