<> <> <> <> <> <> <> <> <> Added HScrollProc to viewer class. Added parent field to viewer class. Added superClass parameter to ViewerOps.RegisterViewerClass. (Note: implementation doesn't handle it yet!) Added ViewerOps.IsClass. (Note: not implemented yet!) Added Buttons.GetClientData. Added clientData parameter to Buttons.Create. Buttons.SetClientData now works. The notify proc called by a button click passes the button instead of NIL for the viewer. In ViewerOpsImplA, added ErrorType parameter to fatalViewersError. This error is no longer raised under a column lock. Several cosmetic changes to Menus: changed capitalization of MenuEntryTrigger items; renamed `notrigger' to `none'; changed `InActive' to `Inactive'. Added 'id' field to ViewerRec. Moved MenuEntryDisplayOp from ViewerClasses (why was it there?) to Menus. A ViewerClasses.SaveProc now returns a boolean to indicate whether it succeeded. ViewerOpsImplB.SaveViewer refrains from resetting newVersion and newFile if the save failed.