As the Apple II (or rather the 6502 chip) is little-endian, meaning the
least significant byte is the first byte you read going forward, rather
than the last byte.
Criterion's init and fini config options allow us to register setup and
teardown functions. We now use this to register the common cpu variable
for the mos6502 tests, albeit through the use of a global variable.
Doing so necessitated that each of the different test files have their
own suites, due to some implementation details in Criterion, but this is
No Big Deal.
