Move tokenizer and tree construction suites into one method each.

- Xcode would not report failures in tree construction tests or tokenizer tests.
- Unless the tests were named nicely, in which case they'd get added to the
  navigator.
- Then Xcode had a tough time with 8000+ test methods. At least if they're all
  in one method then they run and failures are reported as usefully as they
  were before.
Fix spurious parse error in tokenizer.

- Could accidentally ignore only half of a surrogate pair.
Fix parsing tree construction test with empty document.
Add Travis CI support.
Fix errors compiling for 32-bit.