Add an :EditBookmarks command to edit the bookmarks file (#954)

* Add a new NERDTree buffer command to edit the bookmarks file.

* Update the mini-help panel with missing bookmark commands.

* Update the help file with the new :EditBookmarks command.

lib/nerdtree/bookmark.vim

@@ -156,6 +156,13 @@ function! s:Bookmark.delete()
     call s:Bookmark.Write()
 endfunction
 
+" FUNCTION: s:Edit() {{{1
+" opens the NERDTreeBookmarks file for manual editing
+function! s:Bookmark.Edit()
+    execute "wincmd w"
+    execute "edit ".g:NERDTreeBookmarksFile
+endfunction
+
 " FUNCTION: Bookmark.getNode(nerdtree, searchFromAbsoluteRoot) {{{1
 " Returns the tree node object associated with this Bookmark.
 " Throws "NERDTree.BookmarkedNodeNotFoundError" if the node is not found.

lib/nerdtree/creator.vim

@@ -26,6 +26,7 @@ function! s:Creator._bindMappings()
     command! -buffer -nargs=0 ClearAllBookmarks call g:NERDTreeBookmark.ClearAll() <bar> call b:NERDTree.render()
     command! -buffer -nargs=0 ReadBookmarks call g:NERDTreeBookmark.CacheBookmarks(0) <bar> call b:NERDTree.render()
     command! -buffer -nargs=0 WriteBookmarks call g:NERDTreeBookmark.Write()
+    command! -buffer -nargs=0 EditBookmarks call g:NERDTreeBookmark.Edit()
 endfunction
 
 " FUNCTION: s:Creator._broadcastInitEvent() {{{1

lib/nerdtree/ui.vim

@@ -119,6 +119,9 @@ function! s:UI._dumpHelp()
         let help .= "\" :OpenBookmark <name>\n"
         let help .= "\" :ClearBookmarks [<names>]\n"
         let help .= "\" :ClearAllBookmarks\n"
+        let help .= "\" :ReadBookmarks\n"
+        let help .= "\" :WriteBookmarks\n"
+        let help .= "\" :EditBookmarks\n"
         silent! put =help
     elseif !self.isMinimal()
         let help ="\" Press ". g:NERDTreeMapHelp ." for help\n"