More source headers harmonization

* fix missing #ifdefs
* remove spaces and page feeds
* follow same set of rules everywhere, with cdio includes coming
  after standard C includes.

test/check_sizeof.c

@@ -14,16 +14,21 @@
      You should have received a copy of the GNU General Public License
      along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
-
 #ifdef HAVE_CONFIG_H
-# include "config.h"
-# define __CDIO_CONFIG_H__ 1
+#include "config.h"
+#define __CDIO_CONFIG_H__ 1
 #endif
 
 #include <assert.h>
+#ifdef HAVE_STDLIB_H
 #include <stdlib.h>
+#endif
+#ifdef HAVE_STRING_H
 #include <string.h>
+#endif
+#ifdef HAVE_STDIO_H
 #include <stdio.h>
+#endif
 #include <math.h>
 
 #include <cdio/iso9660.h>