graphics/twm4nx/src/ciconmgr.cxx: Integrate use of CButtonArray; implement first cut at event handling.
graphics/nxwidgets/src/cbuttonarray.cxx: Add a method to CButtonArray that will allow us to dynamically resize the array (at the cost of losing all button labels).
graphics/twm4nx/src/ciconmgr.cxx: Add some fragments of CButtonArray logic.
graphics/twm4nx/src/cwindow.cxx: Finishes first cut at window event management.
Squashed commit of the following:
Clean-up some include path problems introduced with the previous set of changes.
app/include/graphics, apps/NxWidgets/UnitTests: Update include paths for file in new location.
apps/NxWidgets/nxwidgets and nxwm: Update include paths for file in new location.
apps/graphics/NxWidgets: Move nxwidgets and nxwm include/ directories to apps/include/graphics
