Use :mode only in neovim. MacVim still needs to use :redraw! (#1019)

* Use :mode only in neovim. MacVim still needs to use :redraw!

* Make nerdtree#redraw do both redraw and redraw! based on a parameter.

* Make bang a required parameter.

* Replace all redraw statments with call nerdtree#redraw function calls.

* Update version in change log.

autoload/nerdtree/ui_glue.vim

@@ -254,7 +254,7 @@ function! s:deleteBookmark(bookmark)
 
     let l:choices = "&Yes\n&No"
 
-    echo | redraw
+    echo | call nerdtree#redraw(0)
     let l:selection = confirm(l:message, l:choices, 1, 'Warning')
 
     if l:selection != 1
@@ -266,7 +266,7 @@ function! s:deleteBookmark(bookmark)
         call a:bookmark.delete()
         silent call b:NERDTree.root.refresh()
         call b:NERDTree.render()
-        echo | redraw
+        echo | call nerdtree#redraw(0)
     catch /^NERDTree/
         call nerdtree#echoWarning('could not remove bookmark')
     endtry
@@ -577,7 +577,7 @@ function! s:refreshRoot()
     call nerdtree#exec(g:NERDTree.GetWinNum() . "wincmd w")
     call b:NERDTree.root.refresh()
     call b:NERDTree.render()
-    redraw
+    call nerdtree#redraw(0)
     call nerdtree#exec(l:curWin . "wincmd w")
     call nerdtree#echo("")
 endfunction