title: .gitignore files not ignored when pulling remote changes
body: <p>I have some files that I don't want to share between my repositories. I added them to <code>.gitignore</code> at the root of my project :</p>
  
  <pre><code># Specifies intentionally untracked files to ignore when using Git
  # http://git-scm.com/docs/gitignore
  # ...
  .idea/
  </code></pre>
  
  <p>And yet I keep getting this error when pulling remote changes using <code>git pull</code> : </p>
  
  <pre><code>error: Your local changes to the following files would be overwritten by merge :
        .idea/workspace.xml
  Please, commit your changes or stash them before you can merge.
  Aborting
  </code></pre>
  
  <p>I have seen some questions about this error message, but they were about overwriting the files. I want to <strong>ignore</strong> the changes (I don't want git to track them at all and I don't want git to change my local files).</p>
  
  <p>What am I doing wrong ? Maybe the problem is I created the <code>.gitignore</code> file <em>after</em> I had already committed the files I wanted to ignore, and I need to remove them from the repo somehow...?</p>