Changes in version 0.1.0                        

First release.

  - A jump height, a takeoff velocity or a net impulse read in R carries
    the rule that produced it, the parameters that rule read, and
    whether each value was stated by the caller or supplied by the rule.
  - Reading a shortened property name is an error rather than a
    neighbouring property's value, and coercing a measured value to a
    bare number asks for @value by name.
  - A rule that declines raises a condition classed by its code, so
    tryCatch() can branch on one code or on every refusal, and every
    field is read by its whole name.
  - The registry ships inside the package. pf_registry()@census counts
    each population apart, with each derived count beside the
    denominator it was taken over.
  - A force file is read by the engine, with the delimiter and the force
    column stated by the caller and reported back along with two counts:
    the samples that matched the sentinel convention, and the samples
    that carried no number at all.
  - The R surface binds the engine through extendr. The boundary carries
    structured data as JSON and the force trace as a raw double vector.