Qt Creator Plugin HOWTO documentation first and second cut

Signed-off-by: Abhishek Patil <abhishek.patil@vcreatelogic.com>

Merge-request: 145
Reviewed-by: con <qtc-committer@nokia.com>

doc/examples/progressbar/progressbarplugin.cpp

@@ -0,0 +1,36 @@
+#include "progressbarplugin.h"
+#include "headerfilterprogress.h"
+
+#include <QtPlugin>
+#include <QStringList>
+
+ProgressBarPlugin::ProgressBarPlugin()
+{
+   // Do nothing
+}
+
+ProgressBarPlugin::~ProgressBarPlugin()
+{
+    // Do notning
+}
+
+void ProgressBarPlugin::extensionsInitialized()
+{
+    // Do nothing
+}
+
+bool ProgressBarPlugin::initialize(const QStringList& args, QString *errMsg)
+{
+    Q_UNUSED(args);
+    Q_UNUSED(errMsg);
+
+    addAutoReleasedObject( new HeaderFilterProgress);
+    return true;
+}
+
+void ProgressBarPlugin::shutdown()
+{
+    // Do nothing
+}
+
+Q_EXPORT_PLUGIN(ProgressBarPlugin)