#38 update menus when clicking in tables

When I was developing a suite it would have been useful
if the menu items would have updated when clicking on
the items of a table.

With a feature like this it would be possible to create
menu items that change based on what item of a table
has been clicked.

I think part of the solution is to fiddle with
(**shellwindowinfo).selectioninfo.fldirty = true; at
the right time. Perhaps somewhere around
tablewindow.c: 560 in the tableverbmousedown function.
There are several variations on how shellwindowinfo is
accessed.

I tried hacking something together but I wasn't able to
figure it out.