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/rsa_verify.c b/programs/pkey/rsa_verify.c
index 4b43380..7d94451 100644
--- a/programs/pkey/rsa_verify.c
+++ b/programs/pkey/rsa_verify.c
@@ -29,15 +29,19 @@
 #if defined(POLARSSL_PLATFORM_C)
 #include "polarssl/platform.h"
 #else
+#include <stdio.h>
 #define polarssl_printf     printf
 #endif
 
-#include <string.h>
-#include <stdio.h>
-
+#if defined(POLARSSL_BIGNUM_C) && defined(POLARSSL_RSA_C) &&\
+    defined(POLARSSL_SHA256_C) && defined(POLARSSL_FS_IO)
 #include "polarssl/rsa.h"
 #include "polarssl/sha1.h"
 
+#include <stdio.h>
+#include <string.h>
+#endif
+
 #if !defined(POLARSSL_BIGNUM_C) || !defined(POLARSSL_RSA_C) ||  \
     !defined(POLARSSL_SHA256_C) || !defined(POLARSSL_FS_IO)
 int main( int argc, char *argv[] )