initial ch09 commit
ex 9.2, 9.3, 9.4
ex 9.6, 9.7, 9.8
initial 9.9 (JSON Parser commit)
ex 9.9 JSON Parser books solution
initial ex 9.12
ex 9.13

ex 9.13
JSONApp
scope, label, attempt, or, flatMap and some ops were not lazy enough
ex 9.15 run method
ex 9.16 books solution
clean ups.
giving up on a sliceoptimized parser