update wizard template

- on Windows the export is required, while on Unix everything
  gets exported by default.
- for Qt5 based Qt Creator we need the specification of the
  json file.

Change-Id: I1e8055fcb2b81d42369f906e1ba42a4c2b811553
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

share/qtcreator/templates/wizards/qtcreatorplugin/myplugin.h

@@ -8,9 +8,10 @@
 namespace %PluginName% {
 namespace Internal {
 
-class %PluginName%Plugin : public ExtensionSystem::IPlugin
+class %PluginName:u%SHARED_EXPORT %PluginName%Plugin : public ExtensionSystem::IPlugin
 {
     Q_OBJECT
+    Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QtCreatorPlugin" FILE "%PluginName%.json")
 
 public:
     %PluginName%Plugin();