branch: don't warn about branches if repository has multiple branches already This warning exists to prevent git users from prematurely polluting their namespace when trying out Mercurial. But for repos that already have multiple branches, understanding what branches are is not optional so we should just shut up.

transaction: really fix _addbackupentry key usage (issue4684) The fix in fd905b2bea59 is actually wrong. We now use the filename to match what '_addentry'. This whole untested code is quite suspicious. This seems to point that no one is ever running 'tr.find' for a backup file.