added byteswap implementation for Mac to work

c-code/binary_storage.c

 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
-#include <byteswap.h>
+/* #include <byteswap.h> */
 #include <sys/time.h>
 #include "binary_storage.h"
 

c-code/binary_storage.h

 #include <stdint.h>
+
+#if HAVE_BYTESWAP_H
+#include <byteswap.h>
+#else
+#define bswap_16(value) \
+((((value) & 0xff) << 8) | ((value) >> 8))
+
+#define bswap_32(value) \
+(((uint32_t)bswap_16((uint16_t)((value) & 0xffff)) << 16) | \
+(uint32_t)bswap_16((uint16_t)((value) >> 16)))
+
+#define bswap_64(value) \
+(((uint64_t)bswap_32((uint32_t)((value) & 0xffffffff)) \
+<< 32) | \
+(uint64_t)bswap_32((uint32_t)((value) >> 32)))
+#endif
+
 typedef struct tagset {
   char **data;
   size_t num;
@@ -19,6 +36,3 @@ typedef struct storage {
 BinaryStorage bs_open(char* filename);
 int write_record(BinaryStorage *bs, char* name, TSTMP timestamp, double value, TAGS *tags);
 void bs_close(BinaryStorage *bs);
-
-
-