Disable copy constructor and assignment operator.

Libs/PluginFramework/ctkPlugin.h

@@ -74,6 +74,7 @@ class ctkPluginPrivate;
 class CTK_PLUGINFW_EXPORT ctkPlugin {
 
   Q_DECLARE_PRIVATE(ctkPlugin)
+  Q_DISABLE_COPY(ctkPlugin)
 
 public:
 

Libs/PluginFramework/ctkPluginFramework.h

@@ -45,6 +45,7 @@ class CTK_PLUGINFW_EXPORT ctkPluginFramework : public ctkPlugin
 {
 
   Q_DECLARE_PRIVATE(ctkPluginFramework)
+  Q_DISABLE_COPY(ctkPluginFramework)
 
 public: