inject QT_VERSION into the evaluator

almost too simple to be right, given the TODO ...

src/plugins/qt4projectmanager/profilereader.cpp

@@ -47,7 +47,6 @@ ProFileReader::~ProFileReader()
 
 void ProFileReader::setQtVersion(QtVersion *qtVersion) {
     addProperties(qtVersion->versionInfo());
-    // ### TODO override QT_VERSION property
 }
 
 bool ProFileReader::readProFile(const QString &fileName)

src/plugins/qt4projectmanager/qtversionmanager.cpp

@@ -758,6 +758,7 @@ void QtVersion::updateVersionInfo() const
     QFileInfo qmake(qmakeCommand());
     if (qmake.exists()) {
         static const char * const variables[] = {
+             "QT_VERSION",
              "QT_INSTALL_DATA",
              "QT_INSTALL_LIBS",
              "QT_INSTALL_HEADERS",