A hearing in State Supreme Court in Riverhead this week may have been the beginning of the end of an ongoing battle between East Hampton Town and the owners of Cyril’s Fish House, the popular eatery and bar on Napeague, but the case is not over yet. The town is seeking a preliminary injunction to prevent the owners, Michael Dioguardi and Cyril Fitzsimons, from operating a business in any other form than existed in 1984, when it was a small roadside cafe. They, in turn, have brought suit against the town for what they say is malicious prosecution and abuse of process.