Move 'hooks' parameter into buffers (parse/print)

tests/parse_number.c

@@ -45,7 +45,7 @@ static void assert_is_number(cJSON *number_item)
 
 static void assert_parse_number(const char *string, int integer, double real)
 {
-    parse_buffer buffer = { 0, 0, 0, 0 };
+    parse_buffer buffer = { 0, 0, 0, 0, { 0, 0, 0 } };
     buffer.content = (const unsigned char*)string;
     buffer.length = strlen(string) + sizeof("");