debugcommands: support connecting to HTTP peers
Now that we have the plumbing for logging socket activity, let's hook
it up to `hg debugwireproto` so we can collect low-level activity on
sockets.
The new code is a bit incomplete. But it is better than nothing:
`hg debugwireproto` is still heavily evolving.
The added test demonstrates some interesting behavior. For example,
we're calling socket.makefile() and doing I/O on that. TIL. We're also
sending an "Accept-Encoding: identity" request header.
Differential Revision: https://phab.mercurial-scm.org/D2726
% 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: [3, 7, 8, 1, 4, 0, 2]
% lazy ancestor set for [1, 3], stoprev = 0, inclusive = False
membership: [1, 0]
iteration: [0, 1]
% lazy ancestor set for [11, 13], stoprev = 0, inclusive = True
membership: [11, 13, 7, 8, 3, 4, 1, 0]
iteration: [11, 13, 3, 7, 8, 1, 4, 0, 2]
% lazy ancestor set for [11, 13], stoprev = 6, inclusive = False
membership: [7, 8]
iteration: [7, 8]
% lazy ancestor set for [11, 13], stoprev = 6, inclusive = True
membership: [11, 13, 7, 8]
iteration: [11, 13, 7, 8]