Implement the g:NERDTreeMarkBookmarks setting

The setting is self-explanatory. See the added documentation for further
details.

doc/NERD_tree.txt

@@ -845,6 +845,15 @@ If set to 0, the bookmarks list is not sorted.
 If set to 1, the bookmarks list is sorted in a case-insensitive manner.
 If set to 2, the bookmarks list is sorted in a case-sensitive manner.
 
+------------------------------------------------------------------------------
+                                                     *'NERDTreeMarkBookmarks'*
+Values: 0 or 1
+Default: 1
+
+If set to 1, Bookmarks will be specially marked whenever the NERDTree is
+rendered. Users of the |'NERDTreeMinimalUI'| setting may prefer to disable
+this setting for even less visual clutter.
+
 ------------------------------------------------------------------------------
                                                        *'NERDTreeMouseMode'*
 Values: 1, 2 or 3.

lib/nerdtree/path.vim

@@ -52,7 +52,7 @@ function! s:Path.cacheDisplayString() abort
             call add(self._bookmarkNames, i.name)
         endif
     endfor
-    if !empty(self._bookmarkNames)
+    if !empty(self._bookmarkNames) && g:NERDTreeMarkBookmarks == 1
         let self.cachedDisplayString .= ' {' . join(self._bookmarkNames) . '}'
     endif
 

plugin/NERD_tree.vim

@@ -57,6 +57,7 @@ call s:initVariable("g:NERDTreeBookmarksFile", expand('$HOME') . '/.NERDTreeBook
 call s:initVariable("g:NERDTreeBookmarksSort", 1)
 call s:initVariable("g:NERDTreeHighlightCursorline", 1)
 call s:initVariable("g:NERDTreeHijackNetrw", 1)
+call s:initVariable('g:NERDTreeMarkBookmarks', 1)
 call s:initVariable("g:NERDTreeMouseMode", 1)
 call s:initVariable("g:NERDTreeNotificationThreshold", 100)
 call s:initVariable("g:NERDTreeQuitOnOpen", 0)