Transfer functions

[shawn-mcadam]

First draft of the nonuniform lookup tables along with the transfer functions we'll use to build them.

[kevinrichardgreen]

On running run_experiment.sh, this PR aborts on a free() call at the end:

free(): invalid next size (fast)
./run_experiment.sh: line 20: 2527481 Aborted                 (core dumped) ./experiment 0.001 30.0 1e-2 10 1000000 19

in both gcc and clang.

In release mode, I can find that this is happening within the ~HornersFunctor() destructor (?? How is that a thing, it looks to be default ??). With debugging flags, gdb doesn't report the stack on abort.

[shawn-mcadam]

Ah, yes I remember that segfault being a thing (and I still don't understand why). I think the transfer functions became uncompilable with gcc in the openmp pr which I did not realize until very recently. These problems should be gone now that I've simplified the transfer functions.