2014-04-05-07.57.03: src/lib/x-kit/widget/gui/gui-tree.pkg: Added slots for look-imp endstate oneshots.  src/lib/x-kit/widget/gui/gui-boss-imp.pkg: Fill in those slots when building Gui_Tree instances.
2014-04-05-08.09.31: src/lib/x-kit/widget/gui/gui-boss-imp.pkg: end_gui(): Use previous when reconstructing Gui_Plan instances from Gui_Tree instances.