Suppose you have two files, M.lyx and C.lyx, with M the default master
for C.
Open C. Now M is open and hidden.
Show M.
Close M.
Both M and C close. This is not intuitive.
If, on the other hand, you close C, then it is simply hidden.
This is trunk. In 1.6, there is basically no way to close a master and
all of its children, so in a sense this is an improvement. But closing
everything when you close the master is a surprise.
So: Either we need to have separate "Close" and "Hide" possibilities for
the master---this is already in the context menu---or else we need to
pop a dialog in these cases: Do you want to hide this tab, or close the
master and all its children?
Richard
