Update Commentary header.
(tree-widget-theme-name): Ignore parent themes.
(tree-widget-set-parent-theme): New function.
(tree-widget-set-theme): Use it.
(tree-widget-set-image-properties): Move definition. Does nothing
if image properties have already been set.
(tree-widget-image-properties): Move definition. Receive an image
name. Set the :pointer property.
(tree-widget-lookup-image): Doc fix. Search in parent themes.
Don't set the :pointer image property.
(tree-widget-convert-widget): New function. Handle :dynargs
compatibility here.
(tree-widget): Use it to :convert-widget. Add the :expander-p
predicate to control when the :expander function is entered.
Thanks to Ken Manheimer <ken.manheimer@gmail.com> for the idea.
(tree-widget-value-create): Handle :expander-p. widget-apply
:expander.
(tree-widget-expander-p): New function. Default value of the
:expander-p property.