title: Setting netrw like NERDTree
body: <ol>
  <li><p>I used <code>nmap &lt;silent&gt; &lt;f2&gt; :NERDTreeToggle&lt;cr&gt;</code> to toggle nerdtree window. How can I do the same with netrw?</p></li>
  <li><p>nerdtree window is not shown in the buffer list(<code>:ls</code>). netrw is listed in the buffer list. How can I make it not listed?</p></li>
  <li><p><code>:bn</code> command works but <code>:bp</code> command does not work in the netrw window. Is this a bug?</p></li>
  </ol>