mh_mbox: fix on Windows.

The 2 main issues were that the files were fopen'd in text mode, and that
the std-based SimpleRegexp implementation was wrong (match instead of search).
Also, make sure that we are using 64 bits interfaces.

src/utils/pathut.cpp

@@ -1,4 +1,4 @@
-/* Copyright (C) 2004 J.F.Dockes
+/* Copyright (C) 2004-2019 J.F.Dockes
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU Lesser General Public License as published by
  *   the Free Software Foundation; either version 2.1 of the License, or
@@ -57,9 +57,9 @@
 #include "safesysstat.h"
 #include "transcode.h"
 
-#define STAT _wstat
-#define LSTAT _wstat
-#define STATBUF _stat
+#define STAT _wstati64
+#define LSTAT _wstati64
+#define STATBUF _stati64
 #define ACCESS _waccess
 
 #else // Not windows ->
@@ -656,7 +656,7 @@ bool path_makepath(const string& ipath, int mode)
     path = "/";
     for (const auto& elem : elems) {
 #ifdef _WIN32
-        if (path == "/" && path_strlookslikedrive(*it)) {
+        if (path == "/" && path_strlookslikedrive(elem)) {
             path = "";
         }
 #endif