Prevent header from being included multiple times

git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@623 632fc199-4ca6-4c93-a231-07263d6284db

turbojpeg.h

@@ -26,6 +26,9 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#ifndef __TURBOJPEG_H__
+#define __TURBOJPEG_H__
+
 #if defined(_WIN32) && defined(DLLDEFINE)
 #define DLLEXPORT __declspec(dllexport)
 #else
@@ -772,3 +775,5 @@ DLLEXPORT int DLLCALL tjDecompress(tjhandle handle,
 #ifdef __cplusplus
 }
 #endif
+
+#endif