cleanup programs
Clean up the contents of programs, add more guards to includes, move all
defines to the top of the top of files, remove some unused includes
diff --git a/programs/pkey/mpi_demo.c b/programs/pkey/mpi_demo.c
index b5ae13e..a6d1198 100644
--- a/programs/pkey/mpi_demo.c
+++ b/programs/pkey/mpi_demo.c
@@ -29,13 +29,16 @@
#if defined(POLARSSL_PLATFORM_C)
#include "polarssl/platform.h"
#else
+#include <stdio.h>
#define polarssl_printf printf
#endif
-#include <stdio.h>
-
+#if defined(POLARSSL_BIGNUM_C) && defined(POLARSSL_FS_IO)
#include "polarssl/bignum.h"
+#include <stdio.h>
+#endif
+
#if !defined(POLARSSL_BIGNUM_C) || !defined(POLARSSL_FS_IO)
int main( int argc, char *argv[] )
{