Add --noinstantiate to qmlplugindump

This flag allows you to run qmlplugindump on plugins which cannot safely
create objects, such as plugins with unusual requirements or missing
essential dependencies.

Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
(cherry picked from commit 0462193b6fb97fbe7ccde496c33d82d4d5fce8c0)

Change-Id: I0d1ff7f94e00a8aab94c0aff012d78db5193400f
Reviewed-by: Alan Alpert <aalpert@blackberry.com>