vim-patch:7.4.457 #1713

Problem:  Using getchar() in an expression mapping may result in
          K_CURSORHOLD, which can't be recognized.
Solution: Add the <CursorHold> key.  (Hirohito Higashi)

https://code.google.com/p/vim/source/detail?r=v7-4-457

src/nvim/version.c

@@ -280,7 +280,7 @@ static int included_patches[] = {
   //460 NA
   //459 NA
   //458,
-  //457,
+  457,
   456,
   455,
   454,