Purge out include files in exported headers

src/libs/extensionsystem/pluginerrorview.h

@@ -31,12 +31,12 @@
 #define PLUGINERRORVIEW_H
 
 #include "extensionsystem_global.h"
-#include "pluginspec.h"
 
 #include <QtGui/QWidget>
 
 namespace ExtensionSystem {
 
+class PluginSpec;
 namespace Internal {
 namespace Ui {
     class PluginErrorView;