Support configurable library location in qbs build.

And also in the qbs sub-project (for the qbs and qmake builds). This
becomes possible with the qbs submodule update that is part of this
patch.

Change-Id: I8347a8c04a52bcb0682f32d808fb61a90ef3ba72
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

src/plugins/qbsprojectmanager/qbsproject.cpp

@@ -727,7 +727,7 @@ QString QbsProject::pluginsBaseDirectory() const
     if (!qbsInstallDir.isEmpty())
         return qbsInstallDir + QLatin1String("/lib/");
     return QDir::cleanPath(QCoreApplication::applicationDirPath()
-                           + QLatin1String("/../lib/qtcreator"));
+                           + QLatin1String("/../" IDE_LIBRARY_BASENAME "/qtcreator"));
 }
 
 } // namespace Internal