title: VIM - add a vcs flag for current file
body: <p>I want to add a flag next to the filename on the statusline.</p>
  
  <p>e.g:</p>
  
  <p><code>filename M</code>   for modified<br>
  <code>filename A</code>   for added<br>
  <code>filename ??</code>  for untracked  </p>
  
  <p>Essentially, is there something similar to the flag <code>%m</code>? if not, how should I go about this to quickly fetch the vcs status of the current file?</p>