Move code to the "src" subdirectory

src/crc.h

@@ -0,0 +1,9 @@
+#ifndef _CRC_
+#define _CRC_
+
+#include <stdio.h>
+
+unsigned long CRC_Buffer(unsigned char *buffer, int len, unsigned long crc);
+unsigned long CRC_File(FILE *file);
+
+#endif