Unconditional include of stdint.h

I think stdint.h is a linux-ism, and certainly in the configure script,
including of this file is conditional, as follows:

#include <sys/types.h>
#ifdef HAVE_STDINT_H
#  include <stdint.h>
#elif defined (HAVE_INTTYPES_H)
#  include <inttypes.h>
#endif

Although, as always, I'm never sure if this is because autoconf/libtool is
outta date on my system. I'm pretty sure they dont generally touch the contents
of .c files, so I think this is a valid bug.

Nick