Win32/MinGW port

[Pavel Tsekov]

Hello, Pavel!

>> Current version is randomly freezing (not responding
>> to keyboard). That looked harder to debug than native build :)

PR> This patch fixes it.  Yes, it was hard to debug (2 hours).

Cool! :)

[snip]

PR> Somebody is blocking SIGCHLD, so even old_mask has SIGCHLD blocked,
PR> therefore the subsequent sigsuspend() call hangs forever.  I'm not sure if
PR> it's going to be the final fix (I'm not applying it yet), but it should be
PR> a reasonably good workaround for Cygwin users for now.

It is interesting that this behaviour appears randomly - you can work
for 10 minutes and then get the hang, or you can get it at the very
beggining.