NAME
valid_hide - allows or disallows objects to hide and see hidden objects
SYNOPSIS
int valid_hide(object ob);
DESCRIPTION
Add valid_hide to master.c in order to allow objects to hide themselves,
or see other objects that have hidden themselves. When an object tries to
use the set_hide() efun to hide itself, valid_hide will be called with the
object that is wanting to hide as the sole parameter. It should return 1
to allow it, or 0 to not allow it. The same call takes place when it needs
to be determined if a certain object should be able to see hidden objects.