modelbased 0.9.0

Breaking Changes

• The default package used for estimate_means(), estimate_slopes() and
  estimate_contrasts() is now marginaleffects. You can set your preferred
  package as backend using either the backend argument, or in general by setting
  options(modelbased_backend = "marginaleffects") or
  options(modelbased_backend = "emmeans").

• Deprecated argument and function names have been removed.

• Argument fixed has been removed, as you can fix predictor at certain values
  using the by argument.

• Argument transform is no longer used to determine the scale of the predictions.
  Please use predict instead.

• Argument transform is now used to (back-) transform predictions and confidence
  intervals.

• Argument method in estimate_contrasts() was renamed into comparison.

• All model_*() alias names have been removed. Use the related get_*()
  functions instead.

• The show_data argument in plot() defaults to FALSE.

Major Changes

• The "marginaleffects" backend is now fully implemented and no longer
  work-in-progress. You can set your preferred package as backend using
  either the backend argument, or in general by setting
  options(modelbased_backend = "marginaleffects") or
  options(modelbased_backend = "emmeans").

• All estimate_*() functions get a predict argument, which can be used
  to modulate the type of transformation applied to the predictions (i.e. whether
  predictions should be on the response scale, link scale, etc.). It can also
  be used to predict auxiliary (distributional) parameters.

• estimate_means() and estimate_contrasts() get a estimate argument,
  to specify how to estimate over non-focal terms. This results in slightly
  different predicted values, each approach answering a different question.

• estimate_contrasts() gains a backend argument. This defaults to
  "marginaleffects", but can be set to "emmeans" to use features of that
  package to estimate contrasts and pairwise comparisons.

• estimate_expectation() and related functions also get a by argument, as
  alternative to create a datagrid for the data argument.

• Many functions get a verbose argument, to silence warnings and messages.

Bug fixes

• estimate_contrasts() did not calculate contrasts for all levels when the
  predictor of interest was converted to a factor inside the model formula.

• Fixed issue in estimate_contrasts() when comparsison (formerly: method)
  was not "pairwise".