title: What do all the changes to .xuserstate and .xcscheme files represent?
body: <p>Whenever I check in changes to my OS X app Xcode 4 projects into git, a lot of lines of files like these get changed with practically every commit</p>
  
  <pre><code> .../UserInterfaceState.xcuserstate                 | 3927 ++++++++++++++++++++
   .../test.xcuserdatad/xcschemes/Deployment.xcscheme |   72 +
   .../test.xcuserdatad/xcschemes/Hush.xcscheme       |   76 +
   .../xcschemes/xcschememanagement.plist   
  </code></pre>
  
  <p>Is this stuff necessary to put under version control? The changes to *.xcuserstate clutter up the output of <code>git log -p</code> so much.</p>