* Add configs that test multithreading, LDM, and setting explicit
  parameters.
* Update the `compress cctx` method to accept `ZSTD_parameters`.
* Compile against the multithreaded `libzstd.a`.
* Update `results.csv` for the new configs.

Unless you think there are more configs/methods I should test, I think
we have a fairly wide set of configs/methods, so I'll pause adding
more for now.