Remove problems with fishd under Cygwin.

Yes, it's an awful hack, but IPC support (and fork support as well -
even FAQ mentions that, and suggests "restarting process" to solve the
problem (http://cygwin.com/faq/faq.html#faq.using.fixing-fork-failures),
but let's ignore that for now) is simply broken in Cygwin. Having to try
to do exactly same thing in Cygwin, just so perhaps it will work is a
completely normal thing (not). I love Windows.
Merge remote-tracking branch 'upstream/master'