title: CFBundleTypeIconFile Icon not showing for given file extension
body: <p>I have the following Info.plist for my application, the problem is files i save with the extension myapp do not seem to pick up on my MyApp icon which i have created from an icon set (application correctly uses icon) so guessing there is something wrong in the plist. </p>
  
  <p>I am assuming if I got this working when running my application at some point documents that I have save will suddenly show with the given icon.</p>
  
  <p>Incase this matters, the document is saved from a set of NSCoder based classes. Clicking these documents also opens my application and loads the file correctly, so confused what I am missing to get Icon to show on the files.... </p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"&gt;
  &lt;plist version="1.0"&gt;
  &lt;dict&gt;
      &lt;key&gt;CFBundleDevelopmentRegion&lt;/key&gt;
      &lt;string&gt;en&lt;/string&gt;
      &lt;key&gt;CFBundleDocumentTypes&lt;/key&gt;
      &lt;array&gt;
          &lt;dict&gt;
              &lt;key&gt;CFBundleTypeExtensions&lt;/key&gt;
              &lt;array&gt;
                  &lt;string&gt;myapp&lt;/string&gt;
              &lt;/array&gt;
              &lt;key&gt;CFBundleTypeIconFile&lt;/key&gt;
              &lt;string&gt;MyApp&lt;/string&gt;
              &lt;key&gt;CFBundleTypeOSTypes&lt;/key&gt;
              &lt;array&gt;
                  &lt;string&gt;ASWM&lt;/string&gt;
              &lt;/array&gt;
              &lt;key&gt;CFBundleTypeName&lt;/key&gt;
              &lt;string&gt;MyApp project file&lt;/string&gt;
              &lt;key&gt;CFBundleTypeRole&lt;/key&gt;
              &lt;string&gt;Editor&lt;/string&gt;
          &lt;/dict&gt;
      &lt;/array&gt;
      &lt;key&gt;CFBundleExecutable&lt;/key&gt;
      &lt;string&gt;${EXECUTABLE_NAME}&lt;/string&gt;
      &lt;key&gt;CFBundleIconFile&lt;/key&gt;
      &lt;string&gt;MyApp&lt;/string&gt;
      &lt;key&gt;CFBundleIdentifier&lt;/key&gt;
      &lt;string&gt;com.workmonkeys.${PRODUCT_NAME:rfc1034identifier}&lt;/string&gt;
      &lt;key&gt;CFBundleInfoDictionaryVersion&lt;/key&gt;
      &lt;string&gt;6.0&lt;/string&gt;
      &lt;key&gt;CFBundleName&lt;/key&gt;
      &lt;string&gt;${PRODUCT_NAME}&lt;/string&gt;
      &lt;key&gt;CFBundlePackageType&lt;/key&gt;
      &lt;string&gt;APPL&lt;/string&gt;
      &lt;key&gt;CFBundleShortVersionString&lt;/key&gt;
      &lt;string&gt;1.0&lt;/string&gt;
      &lt;key&gt;CFBundleSignature&lt;/key&gt;
      &lt;string&gt;ASWM&lt;/string&gt;
      &lt;key&gt;CFBundleVersion&lt;/key&gt;
      &lt;string&gt;1&lt;/string&gt;
      &lt;key&gt;LSApplicationCategoryType&lt;/key&gt;
      &lt;string&gt;public.app-category.developer-tools&lt;/string&gt;
      &lt;key&gt;LSMinimumSystemVersion&lt;/key&gt;
      &lt;string&gt;${MACOSX_DEPLOYMENT_TARGET}&lt;/string&gt;
      &lt;key&gt;NSHumanReadableCopyright&lt;/key&gt;
      &lt;string&gt;Copyright © 2012 Me. All rights reserved.&lt;/string&gt;
      &lt;key&gt;NSMainNibFile&lt;/key&gt;
      &lt;string&gt;MainMenu&lt;/string&gt;
      &lt;key&gt;NSPrincipalClass&lt;/key&gt;
      &lt;string&gt;NSApplication&lt;/string&gt;
  &lt;/dict&gt;
  &lt;/plist&gt;
  </code></pre>