title: How to compare file with its previous version in TortoiseGit
body: <p>I used git bisect to locate the commit that broke stuff. Now I want to compare file with its previous version but when I right click a file in Log Messages window I have only "Compare with base" and "Compare with working tree" and that's useless for me.</p>
  
  <p><strong>How can I easily compare a file from some old commit with its previous version?</strong> </p>
  
  <p>I just want to see what was added/deleted in that particular commit in that file. This what TortoiseSvn normally does when you double click a file in Log Messages window.
  I would prefer to get that outcome using TortoiseGit and WinMerge but if its not possible any other tool is also good.</p>
  
  <p>Thanks in advance.</p>