Since we now canonicalize WSAEWOULDBLOCK into EAGAIN there is
no longer any need to explicitly check EWOULDBLOCK for Win32.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add a QIOChannel subclass that is capable of operating on things
that are files, such as plain files, pipes, character/block
devices, but notably not sockets.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>