title: qmake command to copy files and folders into output directory
body: <p>I'm developing an app that should build on Windows, Linux and OS X using QtCreator and Qt 5.3. I want to copy all files and subfolders from a folder into output folder. I've got it working for Linux and OS X, but not for Windows. Here's the relevant section of my .pro file:</p>
  
  <pre><code>win32 {
      PWD_WIN = $${PWD}
      DESTDIR_WIN = $${OUT_PWD}
      copyfiles.commands = $$quote(cmd /c xcopy /S /I $${PWD_WIN}\copy_to_output $${DESTDIR_WIN})
  }
  macx {
      copyfiles.commands = cp -r $$PWD/copy_to_output/* $$OUT_PWD
  }
  linux {
      copyfiles.commands = cp -r $$PWD/copy_to_output/* $$OUT_PWD
  }
  QMAKE_EXTRA_TARGETS += copyfiles
  POST_TARGETDEPS += copyfiles
  </code></pre>
  
  <p>The error I'm getting on Windows is "Invalid number of parameters".</p>