QML State Machine plugin: correct URL in Q_PLUGIN_METADATA

org.qt-project.org is redundant

Change-Id: Id6a6794e1fc1e4403b3bfcdebbe06a487f904041
Reviewed-by: Sebastian Sauer <sebastian.sauer@kdab.com>
Reviewed-by: Brett Stottlemyer <bstottle@ford.com>
Reviewed-by: J-P Nurmi <jpnurmi@theqtcompany.com>
Fix leaks in QQuickImageParticle

Make sure that ImageData instances, m_shadowData as well as the
QSGGeometry of particle nodes are destroyed together with their
QQuickImageParticle.

Also implement the assignment operator for QQuickParticleData to
avoid its v8Datum pointer to be copied over to the shadow datum
in getShadowDatum. This would cause a double delete of the
QQuickV4ParticleData when trying to call clearShadows() in the
destructor.

Task-number: QTBUG-36782
Change-Id: Ie03f2be0415daeb7f4f6e5f92295a3ab26a62155
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>