Add a 'tree' chart type and a 'treegroup' function.
Add a 'tree' chart type and a 'treegroup' function.

These allow you to automatically create treemap chart hierarchies using the
levels of your key.  So treegroup=a,b,c gives you a tree with the toplevel
showing all 'a', then a second level showing all 'b' for each 'a', and so
on.

apenwarr/afterquery,apenwarr/afterquery,apenwarr/afterquery,apenwarr/afterquery,apenwarr/afterquery