Parser enhancements:
- Support for "NOT IN"
- Support for array subscripts (e.g. "email_addresses[5]")
- Support for postgresql-style double-colon typecasts (e.g. " 'month'::INTERVAL ")
Bug fixes:
- When formatting an AST, sort options (ASC, NULLS FIRST, etc.) were being comma delimited, which was incorrect.
- Empty argument lists (e.g. "NOW()") were not being parsed correctly.