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

ml_util.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include "ml.h"
+
+#include "linenoise.h"
+
+void setup_linenoise(const MlEnvironment &env);
+void linenoise_line_read(char *line);
+void close_linenoise();
+
+
+void completion(const char *buf, linenoiseCompletions *lc);
+char *hints(const char *buf, int *color, int *bold);