This allows for the tool framework to keep track of a universal
set of conditions for the UI state (enabled/checked/shown) for
controls of actions. It removes the need for the main menubar
menus to be CONDITIONAL_MENUs and be rebuilt on each open,
and instead makes the updates of the check and enabling of
items handled in the native wxWidgets way.
This commit switchs the 3d viewer and kicad project manager window
over to this system.
Ian McInerney