Fixed Windows warnings.

Libs/PluginFramework/ctkPluginTrackerPrivate.h

@@ -31,7 +31,7 @@
 class ctkPluginTracker;
 class ctkPluginContext;
 class ctkTrackedPlugin;
-class ctkPluginTrackerCustomizer;
+struct ctkPluginTrackerCustomizer;
 
 class ctkPluginTrackerPrivate
 {

Libs/PluginFramework/ctkServiceTracker.cpp

@@ -135,7 +135,7 @@ void ctkServiceTracker::close()
     {
       d->context->disconnectServiceListener(outgoing.data(), "serviceChanged");
     }
-    catch (const std::logic_error& e)
+    catch (const std::logic_error& /*e*/)
     {
       /* In case the context was stopped. */
     }

Libs/PluginFramework/ctkServiceTrackerPrivate.h

@@ -31,7 +31,7 @@
 
 class ctkServiceTracker;
 class ctkTrackedService;
-class ctkServiceTrackerCustomizer;
+struct ctkServiceTrackerCustomizer;
 
 class ctkServiceTrackerPrivate {
 

Libs/PluginFramework/ctkTrackedPlugin_p.h

@@ -27,9 +27,10 @@
 
 #include "ctkPluginAbstractTracked_p.h"
 #include "ctkPluginEvent.h"
+#include "ctkPlugin.h"
 
 class ctkPluginTracker;
-class ctkPluginTrackerCustomizer;
+struct ctkPluginTrackerCustomizer;
 
 class ctkTrackedPlugin : public QObject,
     public ctkPluginAbstractTracked<QSharedPointer<ctkPlugin>, ctkPluginEvent>

Libs/PluginFramework/ctkTrackedService_p.h

@@ -27,7 +27,7 @@
 #include "ctkServiceEvent.h"
 
 class ctkServiceTracker;
-class ctkServiceTrackerCustomizer;
+struct ctkServiceTrackerCustomizer;
 
 class ctkTrackedService : public QObject,
     public ctkPluginAbstractTracked<ctkServiceReference, ctkServiceEvent>