system() just calls "sh" not "/bin/sh"

[Christopher Faylor]

The thread in the cygwin list alerted me to the fact that system
calls "sh" rather than "/bin/sh".

The linux man page explicitly says that system should run /bin/sh.
SUSv3 doesn't come out and say that but it seems to imply it.

If I change this then it will be more correct but possibly there will be
later howls of indignation.

Any thoughts on this?  I'm inclined just to change it.  The downside of
changing it are the howls, the upside is that a random 'sh' in your path
will no longer be called and system will be ever-so-slightly faster.

cgf