title: Git remove files from repository, Github and commiters
body: <p>Somebody accidentally checked in 80 megs worth of JPG's into our git repository and pushed it to github central repository.</p>
  
  <p>A few people since pulled these changes.</p>
  
  <p>Apart from shooting the committer, what can I do to remove these images completely from the repository's history and github? And then inflict all changes on other committers.</p>