title: QMAKE_POST_LINK in windows 10 issue
body: <blockquote>
    <p>I have an Qt project wherein I build a lib and then use it in my main
    project. For that purpose in the library's .pro file I need to copy the
    generated libs to a certain folder. And for that purpose I am using
    <em>QMAKE_POST_LINK</em>. The ones I have doesn't seem to work.</p>
  </blockquote>
  
  <pre><code>QML_INSTALL_PATH = C:\Qt\Qt5.7.0\5.7\mingw53_32\qml\Plot
  QMAKE_DIR_SEP = "\\"
  
  WDIR = $$replace(PWD, /, $$QMAKE_DIR_SEP)
  QMAKE_POST_LINK += copy /y ..\Plot\*.*  $$QML_INSTALL_PATH &amp;
  QMAKE_POST_LINK += copy /y $$WDIR\*.qml $$QML_INSTALL_PATH
  </code></pre>