Don't fall through in giant parser switch.
Jump straight from "in cell" to "in body" as appropriate.

Big performance benefit to skipping the redundant -processToken checks.
Replace ConstantArray hack.

Cool hack, but this feels better.
Change IsSpaceCharacterToken to is_whitespace.

- More useful.
- Faster.
Consistently use StringIsEqualToAnyOf.
Fix selecting subset of tests in scheme.
Tidy up test creation and naming.