Fix CR expansion & syn fold enabled by InsertLeave

Benamin Fritz reported the following:

Without the "zv", if the user has syntax folding on, when the mapping
invokes <Esc> the pair of braces which were just separated by a <CR>
could become folded, so that the trailing "o" opens a new line AFTER
the pair.

autoload/delimitMate.vim

@@ -418,7 +418,9 @@ function! delimitMate#ExpandReturn() "{{{
 
 		" Not sure why I used the previous combos, but I'm sure somebody will tell
 		" me about it.
-		return "\<Esc>a\<CR>\<Esc>O"
+		" XXX zv prevents breaking expansion with syntax folding enabled by
+		" InsertLeave.
+		return "\<Esc>a\<CR>\<Esc>zvO"
 	else
 		return "\<CR>"
 	endif