title: List opened files grouped by pending changelist in p4
body: <p>In Cygwin bash, how can I list all files opened in the current workspace grouped by pending changelist (ignoring empty or shelved changelists)?</p>
  
  <p>For example, if I've the following files opened in the following changelists, I wish to display it in this (or similar) format:</p>
  
  <pre><code>1234: Changelist 1234's description
  //path1/file1 1 add  text
  //path2/file2 2 edit text
  
  5678: Changelist 5678's description
  //path2/file3 3 edit xbinary
  </code></pre>
  
  <p><code>p4 opened|sed "s/\([-#()]\|change\)/ /g"|column -t|sort -k 4</code> sort-of groups them by changelist number:</p>
  
  <pre><code>//path1/file1 1 add  1234 text
  //path2/file2 2 edit 1234 text
  //path2/file3 3 edit 5678 xbinary
  </code></pre>
  
  <p>but I'd like to see each changelist number and description as a header.</p>