Change canonpath to not know about repo objects Code in util should not have any knowledge about repo objects

Updated list of contributors.

Document archive download options

Various cleanups for tarball support s/tarball/archive/ query config rather than maintaining a list default all archive support to off use changeset nodes rather than manifest nodes use web:name for archive name don't use rev number in filename, it's not portable refactor manifest lookup bits use finally: clause to delete tmpfile