Show hidden/unmapped/unrealized widgets as grey.
Show hidden/unmapped/unrealized widgets as grey.

It can be a little confusing looking at the widget tree, trying to reconcile
that with what's on the screen. I've found it's much easier to use if widgets
which aren't visible on-screen are shown greyed out in the tree.

Signed-off-by: chipx86 <a3e5bf1e23f9b398fd796b3f030b30fdb8b825f9@chipx86.com>
davidt/gtkparasite,chipx86/gtkparasite,chipx86/gtkparasite,davidt/gtkparasite,GNOME/gtkparasite,GNOME/gtkparasite