0.1.0

  Initial placeholder version.

0.1.2

  Add structs implementing GaloisField and constructors.

  Add README.md and unit tests.

0.1.3

  Add vector operations (no unit testing yet).

  Refine documentation.

0.1.4

  Add new guff::good module, to contain "reasonable" set of optimised
  maths implementations.

  Add optimised GF(2**4) implementation for field poly 0x13 there,
  backed by two generic lookup table types (for inv and mul).

  Fix bug in default implementation when calculating inverses in
  GF(2**4).

  Clean bill of clippy health.