Small fixes in the codebase

* Remove explicit use of Qt::QueuedConnection. As it turns out, when the
  event is emitted by a thread, different from the GUI thread, it is
  automatically enqueued.
* use #ifdef instead of #if

application/gui/properties/propertycollectionwidget.cpp

@@ -70,7 +70,7 @@ namespace campvis {
         _layout->setSpacing(8);
         _layout->setMargin(0);
         setLayout(_layout);
-        connect(this, SIGNAL(s_propertyVisibilityChanged(const AbstractProperty*)), this, SLOT(onWidgetVisibilityChanged(const AbstractProperty*)), Qt::QueuedConnection);
+        connect(this, SIGNAL(s_propertyVisibilityChanged(const AbstractProperty*)), this, SLOT(onWidgetVisibilityChanged(const AbstractProperty*)));
         connect(this, SIGNAL(propertyAdded(AbstractProperty*)), this, SLOT(addProperty(AbstractProperty*)));
         connect(this, SIGNAL(propertyRemoved(AbstractProperty*, QWidget*)), this, SLOT(removeProperty(AbstractProperty*, QWidget*)));
     }

ext/cgt/shadermanager.cpp

@@ -479,7 +479,7 @@ void Shader::activate() {
 }
 
 void Shader::activate(GLint id) {
-#if CGT_DEBUG
+#ifdef CGT_DEBUG
     if (cgt::getGlInt(GL_CURRENT_PROGRAM) != 0)
         LWARNING("Binding a new Shader while another Shader is active. Do you really want to do this?");
 #endif