[project @ 1998-11-23 15:44:21 by sof]
Extend hConnectTo to also allow output handles to be connected, i.e.,
h1 <- openFile "foo" WriteMode
h2 <- openFile "bar" WriteMode
hConnectTo h1 h2
will cause h1's buffer to be flushed when h2's buffer overflows
(and it is just about to be flushed.) The implementation is currently
not as lazy as that, it flushes h1's buffer regardless of whether h2's
buffer overflows or not.
This is used to connect 'stderr' and 'stdout', i.e., output on
'stderr' will now cause 'stdout' output to (first) be flushed.