There are quite a few variables in the code that are no longer
(or perhaps never were) in use. These were discovered by enabling
compiler warnings for unused variables and cleaning them up.
In most cases where the unused variables were the result
of a function call the call was left but the variable
assignment removed, unless it was obvious that it was
a simple getter with no side effects.
This involved a reorg of the code, to factor and speedup some bits,
as well as using the cache for all modes, and making both modes
usable in the same run.
