connection_fatal(), since the latter is entitled to destroy the
backend so `ssh' may no longer be valid once it returns.
For the Unix port, switch exit(0) to gtk_main_quit() in
notify_remote_exit(), so that we don't exit before the subsequent
connection_fatal()!
[originally from svn r5445]
changing its mouse pointer. Currently this is only used in the (slightly-
arbitrarily-defined) "heavy" bits of SSH-2 key exchange. We override pointer
hiding while PuTTY is busy, but preserve pointer-hiding state.
Not yet implemented on the Mac.
Also switch to frobbing window-class cursor in Windows rather than relying on
SetCursor().
[originally from svn r5303]