chg: upgrade client to use "setumask2" command
No compatibility code is added to the client side, since it's unlikely for
new client to communicate with the old server.
% lazy ancestor set for [], stoprev = 0, inclusive = False
membership: []
iteration: []
% lazy ancestor set for [11, 13], stoprev = 0, inclusive = False
membership: [7, 8, 3, 4, 1, 0]
iteration: [8, 7, 4, 3, 2, 1, 0]
% lazy ancestor set for [1, 3], stoprev = 0, inclusive = False
membership: [1, 0]
iteration: [1, 0]
% lazy ancestor set for [11, 13], stoprev = 0, inclusive = True
membership: [11, 13, 7, 8, 3, 4, 1, 0]
iteration: [13, 11, 8, 7, 4, 3, 2, 1, 0]
% lazy ancestor set for [11, 13], stoprev = 6, inclusive = False
membership: [7, 8]
iteration: [8, 7]
% lazy ancestor set for [11, 13], stoprev = 6, inclusive = True
membership: [11, 13, 7, 8]
iteration: [13, 11, 8, 7]
% lazy ancestor set for [11, 13], stoprev = 11, inclusive = True
membership: [11, 13]
iteration: [13, 11]
% lazy ancestor set for [11, 13], stoprev = 12, inclusive = True
membership: [13]
iteration: [13]
% lazy ancestor set for [10, 1], stoprev = 0, inclusive = True
membership: [2, 10, 4, 5, 0, 1]
iteration: [10, 5, 4, 2, 1, 0]