The regular transfers of productions from the subsidised to the commercial sector  can give the impression that there is not much of a gulf between the interests of public and private money. However, two startlingly contrasting current shows demonstrate just how far apart the ambitions and instincts of the two types of theatre can be.Versailles, the latest offering of Josie Rourke’s increasingly impressive regime at the Donmar Warehouse, is the kind of thing that only an Arts Council-funded venue (and perhaps only a few of those) would do. The author, Peter Gill, now 74, having previously seemed a domestic miniaturist, has now written an epic of public and private life. Versailles is a three-hour, three-act drama that follows the involvement of a young man, Leonard Rawlinson (G