Improvements to Lawrencium paths: - `parse_lawrencium_path` only optionally converts paths to absolute or relative paths. - Added ability to get a relative path from a repo object. - `GetLawrenciumPath` converts path to repo-relative by default, but that can be overridden. Improvements to `Hglog`: - Added `Hgrepolog` command. - Fixed clean-up problems. Miscellaneous: - Removed auto-completion from `Hgdiff` and `Hgdiffsum` command families since the only allowed parameters are revision numbers/hashes/specs. - Code clean-up for `Hgdiff`.