Add support for displaying the fanchart with a different color scheme
 based on the pedigree of the person.
Start of work to compute the fanchart and pedigree views using the graph
 already created for the quilts view.
Add support for disabling display of marriage dates in fanchart
Add support for using gradients when displaying the fanchart
Preserve box height when switching display of marriages in fanchart
The fanchart settings are now initialized by the fanchart itself.
When changing the number of generations in fanchart, use AJAX to load data.

This preserves the current settings of the fanchart.