title: Can't remove file from git commit
body: <p><strong>How do I discard all git commits that haven't been pushed and then force git to not commit anything in the data/ directory?</strong></p>
  
  <p>I'm trying to force overwrite all changes to a project stored on github from my c9.io project.  I accidentally git added some mongodb data files.  I tried to add the data/ directory to .gitignore. I pulled from github to get the updated .gitignore, however when I try and git push, these stubborn files in data/ are still staged for commit.  I also tried git reset, git rebase, git clean and <a href="http://www.thisprogrammingthing.com/2013/fixing-the-this-exceeds-githubs-file-size-limit-of-100-mb-error/">this</a> where I changed dmpfile.sql to pi/data/node-login.1.</p>
  
  <p>Please help I've been at this for hours and I'm really frustrated</p>
  
  <pre><code>Counting objects: 15, done.
  Delta compression using up to 2 threads.
  Compressing objects: 100% (13/13), done.
  Writing objects: 100% (13/13), 150.22 KiB | 92 KiB/s, done.
  Total 13 (delta 6), reused 0 (delta 0)
  remote: warning: File pi/data/local.0 is 64.00 MB; this is larger than GitHub's recommended maximum file size of 50 MB
  remote: warning: File pi/data/node-login.0 is 64.00 MB; this is larger than GitHub's recommended maximum file size of 50 MB
  remote: error: GH001: Large files detected.
  remote: error: Trace: e6ade98208c08b634ed28aefea36dfbb
  remote: error: See http://git.io/iEPt8g for more information.
  remote: error: File pi/data/node-login.1 is 128.00 MB; this exceeds GitHub's file size limit of 100 MB
  To git@github.com:bobbyg603/goddard.git
   ! [remote rejected] master -&gt; master (pre-receive hook declined)
  error: failed to push some refs to 'git@github.com:bobbyg603/goddard.git'
  </code></pre>
  
  <p>.gitignore:</p>
  
  <pre><code>lib-cov
  *.seed
  *.log
  *.csv
  *.dat
  *.out
  *.pid
  *.gz
  
  data/
  
  pids
  logs
  results
  
  npm-debug.log
  node_modules
  
  .project
  .settings
  </code></pre>
  
  <p>Thanks,
  Bobby</p>