Quite a departure from the standard Australian lodge hotel — Thorngrove Manor is a fantasy version of a European castle, complete with turrets, towers and rough stone walls. The interiors carry on in the same baroque vein, with antiques, artworks and architectural details at every turn. Yet in spite of the historical theme, Thorngrove is a thoroughly modern luxury hotel, and deep down has more in common with today’s five-star boutiques than with any drafty old fortress. With just five…