v0.4.1

• Fixed CounterExample::toExamplesCode() emitting non-runnable example code
  for a counterexample with in-body Gen::draw() values: draw#N
  pseudo-arguments are not parameters, so rendered positionally they produced
  an example of the wrong arity. It now throws a LogicException naming the
  draw and pointing at seed replay, following the non-exportable-object
  precedent (#55).
• Fixed Gen::regex() silently compiling escapes outside the supported subset
  (\h, \v, \R, \Q…\E, \0, \x, ...) to literal characters,
  generating strings that do not match the pattern. Unknown alphanumeric
  escapes now throw naming the escape (escaped punctuation stays literal, as
  before); [\b] inside a character class generates a backspace; lazy and
  possessive quantifiers are rejected with an honest message instead of
  "?" has nothing to repeat (#56).
• Fixed corpus seed-entry replay pruning a live regression when the configured
  runs count was lowered below the recorded failing attempt: seed entries now
  store runsBeforeFailure and the replay extends its run count up to the
  recorded attempt. Documents written before the field keep the previous
  behaviour; the on-disk format version is unchanged (#57).