Make use of $$MODULE_PLUGIN_TYPES

This fix build after 48b107ecfe216b93361ee162999e0cd0ee1cee41

Change-Id: I9baacd384e280736c8cb05150bb14ac5549be62f
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>
Minor clean-up for plugin .pro files

Change-Id: Ie17a754db273154f8579a508a244272fb4c0a73f
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>
Do not delete m_filter on the destructor

It is totally unexpected that QDeclarativeOrganizerModel takes
ownership of the filter passed in setFilter given that filter
will coming from the QML side.

Change-Id: Ib0e7453961fdadab40b38acbdda147c462e321db
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>