Bug Fixes and Extra Data

1. Fix a bug with diffs: We were passing the diff as an encoding string to the api. This passes the json dict instead.
2. Add fr volume and page number for SxS
3. Always sort SxS via the effective date
4. Modifies the subpart parsing code to allow for subparts without sections (e.g. reserved subparts)
5. Modifies section header parsing to accept other non-word characters (e.g. a period in one regulation)
6. Allow > 26 unnamed paragraph levels in appendices -- this likely implies other parsing bugs, but we'll be able to see them better by allowing the parser to continue