Path deletion
val v_op : id:id -> mark:mark -> created:B00_std.Time.span -> ?post_exec:(op -> unit) -> ?k:(op -> unit) -> B00_std.Fpath.t -> opv_op declares a path deletion operation, see the corresponding accessors for the semantics of the various arguments.
val v : path:B00_std.Fpath.t -> tv constructs a bare deletion operation.
val path : t -> B00_std.Fpath.tpath d is the path to delete.