Swig bindings for R call fprintf but fail to include stdio.h.

Reported upstream as issue #555:

https://github.com/swig/swig/issues/555

diff -ru swig-3.0.5/Lib/r/rrun.swg swig-3.0.5.new/Lib/r/rrun.swg

--- swig-3.0.5/Lib/r/rrun.swg 2015-01-31 09:51:17.000000000 -0800

+++ swig-3.0.5/Lib/r/rrun.swg 2015-10-23 14:03:31.679583617 -0700

@@ -20,6 +20,7 @@

#include <Rdefines.h>

#include <Rversion.h>

+#include <stdio.h>

#include <stdlib.h>

#include <assert.h>