title: QWT designer plugin is inaccesable via QtCreator built-in designer
body: <p>I've installed QWT 6.1.0 over a Qt 5.0.1. It installed correctly, but I have one problem with QWT Designer plugin: when I accessing QtDesigner separatly it works correct. But when I trying to use it inside a Creator it don't works: there is no qwt widgets in a form, althogh it builds correctly and widgets are displaying on a runtime. </p>
  
  <p>Next system variables are set:
  QT_PLUGIN_PATH = C:\Qwt-6.1.0\plugins
  QMAKEFEATURES = C:\Qwt-6.1.0\features</p>
  
  <p>In "Tools->Form Editor->QtDesigner Plugins" it is written that creator can't find necessary [rocedure</p>