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/util/pem2der.c b/programs/util/pem2der.c
index 74f7a3e..c967e53 100644
--- a/programs/util/pem2der.c
+++ b/programs/util/pem2der.c
@@ -29,21 +29,31 @@
 #if defined(POLARSSL_PLATFORM_C)
 #include "polarssl/platform.h"
 #else
-#define polarssl_printf     printf
-#define polarssl_malloc     malloc
+#include <stdio.h>
 #define polarssl_free       free
+#define polarssl_malloc     malloc
+#define polarssl_printf     printf
 #endif
 
-#include <string.h>
-#include <stdlib.h>
-#include <stdio.h>
-
+#if defined(POLARSSL_BASE64_C) && defined(POLARSSL_FS_IO)
 #include "polarssl/error.h"
 #include "polarssl/base64.h"
 
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#endif
+
 #define DFL_FILENAME            "file.pem"
 #define DFL_OUTPUT_FILENAME     "file.der"
 
+#define USAGE \
+    "\n usage: pem2der param=<>...\n"                   \
+    "\n acceptable parameters:\n"                       \
+    "    filename=%%s         default: file.pem\n"      \
+    "    output_file=%%s      default: file.der\n"      \
+    "\n"
+
 #if !defined(POLARSSL_BASE64_C) || !defined(POLARSSL_FS_IO)
 int main( int argc, char *argv[] )
 {
@@ -170,13 +180,6 @@
     return( 0 );
 }
 
-#define USAGE \
-    "\n usage: pem2der param=<>...\n"                   \
-    "\n acceptable parameters:\n"                       \
-    "    filename=%%s         default: file.pem\n"      \
-    "    output_file=%%s      default: file.der\n"      \
-    "\n"
-
 int main( int argc, char *argv[] )
 {
     int ret = 0;