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
0
0
adding changesets
killed!
transaction abort!
rollback completed
00changelog.d
00changelog.i
data
journal.dirstate