Proposal: overhaul System.Process

[Bryan O'Sullivan]

Neil Mitchell wrote:

> I would have thought (ExitCode,String) was more appropriate.

Yes, definitely.  What happens to stderr with this function, by the way?
 Is it tied to stdout (probably the right thing to do), or to /dev/null,
or is it closed (eek!)?  The haddock should make that clear.

It would be useful if there was a readProcess variant that gave back a
String each for stdout and stderr.

	<b