Use :mode instead of :redraw! when updating menu. (#1016)

* Use :mode instead of :redraw! when updating screen.

In neovim, it will actually clear the whole screen, whereas, redraw!
does not.

* Update version number in change log.

lib/nerdtree/menu_controller.vim

@@ -31,7 +31,7 @@ function! s:MenuController.showMenu()
         let l:done = 0
 
         while !l:done
-            redraw!
+            mode
             call self._echoPrompt()
 
             let l:key = nr2char(getchar())