fixes & enhandcements

(benchmark code..) implemented
repl completion very first version
(string xx) added
some builtin renames
a bit of comments
a bit of cocumentation
(sleep interval) added

clib/linenoise.h

@@ -43,6 +43,8 @@
 extern "C" {
 #endif
 
+#include "stddef.h"
+
 typedef struct linenoiseCompletions {
   size_t len;
   char **cvec;