vim-patch:7.4.247

Problem:    When passing input to system() there is no way to keep NUL and
            NL characters separate.
Solution:   Optionally use a list for the system() input. (ZyX)

https://code.google.com/p/vim/source/detail?r=v7-4-247

Implement write_list_to_string() as well since write_list() only works
on files.

src/nvim/version.c

@@ -394,7 +394,7 @@ static int included_patches[] = {
   //250 NA
   //249,
   //248,
-  //247,
+  247,
   //246,
   245,
   //244,