NO_SOCK_SIGIO define. When it is defined, ctrl-g seems to be picked up more
often, but there are some annoying side effects. Currently it is left off by
default, unless the --enable-cocoa-experimental-ctrl-g option is passed to
-configure. (Has no effect under GNUstep.) This is an area for improvement.
-Also, see the article here and its containing thread:
+configure [option removed Feb 2009]. (Has no effect under GNUstep.)
+This is an area for improvement. Also, see the article here and its
+containing thread:
http://article.gmane.org/gmane.emacs.devel/92021/match=handling%5fsignal