Add replacement for strndup(). MinGW doesn't have it. From Pete Batard again.

lib/driver/abs_path.c

@@ -59,6 +59,21 @@
 # define CharNext(p) ((p) + 1)
 #endif
 
+#ifndef HAVE_STRNDUP
+static inline char *strndup(const char *s, size_t n)
+{
+    char *result;
+    size_t len = strlen (s);
+    if (n < len)
+        len = n;
+    result = (char *) malloc (len + 1);
+    if (!result)
+        return 0;
+    result[len] = '\0';
+    return (char *) strncpy (result, s, len);
+}
+#endif /*HAVE_STRNDUP*/
+
 static char *
 strrdirsep(const char *path)
 {