Version 1.5.0 (native implementation)

ADDED

- Add `n_events` (with option `-N` and default `0`)
  and `rel_stddev` (with option `-S` and default `none`,
  i.e. no active error target) to the main section of the settings.
  Event generation stops only when all three criteria are met.
  ([!180](https://gitlab.com/spice-mc/pepper/-/merge_requests/180),
  ([!209](https://gitlab.com/spice-mc/pepper/-/merge_requests/209))
- Show a time-per-event statistics also for non-zero unweighted events
  at the end of the event generation.
  ([!180](https://gitlab.com/spice-mc/pepper/-/merge_requests/180))
- Very small event generation durations are now shown in ms and µs.
  ([!180](https://gitlab.com/spice-mc/pepper/-/merge_requests/180))
- Allow using multiple `--settings` options.
  ([!203](https://gitlab.com/spice-mc/pepper/-/merge_requests/203))
- Increase unit-test code coverage.
  ([!203](https://gitlab.com/spice-mc/pepper/-/merge_requests/203),
  [!209](https://gitlab.com/spice-mc/pepper/-/merge_requests/209))
- Add support for HepMC3 output to the pepper-h5edit script.
  ([!208](https://gitlab.com/spice-mc/pepper/-/merge_requests/208))

FIXED

- Fix shuffling event samples with `pepper-h5edit`.
  ([!204](https://gitlab.com/spice-mc/pepper/-/merge_requests/204))
- Clarify installation instructions of the LHAPDF dependency.
  ([!203](https://gitlab.com/spice-mc/pepper/-/merge_requests/203))
- Suppress compiler warnings when compiling some 3rd-party components.
  ([!203](https://gitlab.com/spice-mc/pepper/-/merge_requests/203))
- Allow to disable VEGAS (`[phase_space.vegas].disabled = 1`) safely
  between runs.
  ([!189](https://gitlab.com/spice-mc/pepper/-/merge_requests/189))
- [main] Remove a misleading warning about pulling random numbers
  from the device while there is actually no device.
  ([!209](https://gitlab.com/spice-mc/pepper/-/merge_requests/209))
- Report an error if a batch size of zero is used
  during the warm-up phases which would otherwise stall them.
  ([!209](https://gitlab.com/spice-mc/pepper/-/merge_requests/209))

CHANGED

- The default value of `n_batches` is changed from `1` to `0`.
  ([!180](https://gitlab.com/spice-mc/pepper/-/merge_requests/180))
- Remove misleading Q-value warnings during optimisation.
  ([!203](https://gitlab.com/spice-mc/pepper/-/merge_requests/203))
- Improve output for parallel configuration
  and for the final MPI-reduced result.
  ([!209](https://gitlab.com/spice-mc/pepper/-/merge_requests/209))

PERFORMANCE

- The upper size limits for the HDF5 data sets for LHEH5 event output
  are now set to unlimited, instead of using `n_batches * batch_size`,
  which was a very large overestimate.
  ([!180](https://gitlab.com/spice-mc/pepper/-/merge_requests/180))