J.H. Sluijmer theme updates

The page about J.H. Sluijmer Sr. and his son J.H. Sluijmer Jr. has had a major update; extended biographies, a list of works that is close to complete, and a few pictures. And to stay with J.H. Sluijmer Sr., there's a completely new page about the St. Mauritius in Silvolde (see picture) and improved versions of the pages about the St. Isidorus in St. Isidorushoeve, the St. Jacobus de Meerdere in Enschede and the H. Bonifatius en Gezellen in Haaksbergen-Veldmaat.