The `display` method of `SensingMatrixSolution` now has options for
highlighting the largest values if Pandas is found at runtime.

fixes #362 always build matrix in simulation by default. Need a better way of determining this type of switch, as it makes the logic internally in the simulation difficult

Simplify parallel build configuration

See merge request !82

inside a `if __name__ == "__main__":` clause

the build_ext command (now) natively supports parallel builds, so we just need to overload the default to use it, rather than use a homebrewed solution.
this can be configured/disabled using the `CPU_COUNT` environment variable, e.g. `CPU_COUNT=0 python3 build_ext`