Clean up some merge logic - rename mode to branch_merge - use explicit update mode - use negative mtime for updates that set mtime - expand some cryptic variable names - elaborate merge dirstate comments - remove redundant manifest lookup for non-merge case - remove impossible merge case - fix up test cases

#!/bin/sh

hg init
mkfifo p

hg serve --stdio < p &
P=$!
(echo lock; echo addchangegroup; sleep 5) > p &
Q=$!
sleep 1
kill -HUP $P
sleep 1
ls .hg