Windows has a problem when you type ^C to sysex loopback test. (Probably there are many other times where you can interrupt MIDI operations and cause problems.) Added Ctrl-C handler. Trying to prompt for ENTER before exiting and closing console (which might have important error messages) seems to interact with nested calls to getchar(), so prompting for ENTER (which was the default for DEBUG builds) is now removed. Run from the command line to keep the console alive on exit. Now tests pass on Windows.