title: How to show in GNU Screen hardstatus what tab was selected previously?
body: <p>Every time I work in the console I use GNU Screen. I have a custom
  .screenrc file with several settings. Among others I have the setting that
  shows 'tabs' in the bottom:</p>
  
  <pre><code>hardstatus alwayslastline
  hardstatus string "%{= g} %{= w}%-w%{=r}%n %t%{-}%+W"
  </code></pre>
  
  <p>It works well, but I want to add to the tabs some symbol that shows what
  tab was previously active. How can this be done?</p>