patch: return list of modified files even when an exception is raised
The file list is passed in as an argument and updated in place.
This fixes
issue399.
Add new branch info to templater and use it in map-cmdline.default.
The template currently shows old (hg log -b style) branch tags, too,
but not in the same way as the built in changeset_printer.
Show extra changeset info for log/tip/heads/... --debug