changelog: lazily parse manifest node Like the description, we store the raw bytes and convert from hex on access. This patch also marks the beginning of our new parsing method, which is based on newline offsets and doesn't rely on str.split(). Many revsets showed a performance improvement: author(mpm) 0.896565 0.869085 0.868598 desc(bug) 0.887169 0.928164 0.910400 extra(rebase_source) 0.865446 0.871500 0.841644 author(mpm) or author(greg) 1.801832 1.791589 1.731503 author(mpm) or desc(bug) 1.812438 1.851003 1.798764 date(2015) or branch(default) 0.968276 0.974027 0.945792