title: Change the user picture for Git in Xcode
body: <p>Is there any way to change the Git user picture for Xcode5?  </p>
  
  <p>I can change the username and email with command like this:<br>
  <code>xcrun git config --global user.name 'new_user_name'</code><br>
  <code>xcrun git config --global user.email 'new@email.com'</code></p>
  
  <p>But what about the user picture？</p>