Add a DJB2 string hashing function

include/akstdlib.h

@@ -5,6 +5,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdint.h>
 
 akerr_ErrorContext AKERR_NOIGNORE *aksl_fopen(char *pathname, char *mode, FILE **fp);
 akerr_ErrorContext AKERR_NOIGNORE *aksl_fread(void *ptr, size_t size, size_t nmemb, FILE *stream);
@@ -28,4 +29,6 @@ akerr_ErrorContext AKERR_NOIGNORE *aksl_atof(const char *nptr, double *dest);
 
 akerr_ErrorContext AKERR_NOIGNORE *aksl_realpath(const char *restrict path, char *restrict resolved_path);
 
+akerr_ErrorContext AKERR_NOIGNORE *aksl_strhash_djb2(char *str, size_t len, uint32_t *hashval);
+
 #endif