[PATCH 3 of 3] debugdiscovery: add serverlog support

[timeless]

# HG changeset patch
# User timeless <timeless at mozdev.org>
# Date 1451543513 0
#      Thu Dec 31 06:31:53 2015 +0000
# Node ID 2afc775033c96c71e6e2c14f14798cb11d3851aa
# Parent  d97550408d1c5d6afa71b7d24448221d1dce7601
debugdiscovery: add serverlog support

this log seems to do something vaguely useful:
;cg;comment
;cgss;1 2 3 4;5 6 7 8
;unb;1 2 3 4;5 6 7 8

diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -2270,6 +2270,7 @@
     [('', 'old', None, _('use old-style discovery')),
     ('l', 'local_head', [], _('local head changeset'), _('REV')),
     ('r', 'remote_head', [], _('remote head changeset'), _('REV')),
+    ('', 'serverlog', [], _('server log file'), _('FILE')),
     ('', 'nonheads', None,
      _('use old-style discovery with non-heads included')),
     ] + remoteopts,