Add derivative function to Transforms
Pass 'numOffsetsSpreadObs' option from run down to configuration
Fixes bug when combining discrete and continuous when ensemble missing

A non-missing probability value should always be returned when either
the discrete or continuous model returns a missing value for a
threshold. However this did not happen when Discrete model that does not
use the ensemble (e.g.  DiscreteConst) is combined with a Continuous
model that does use the ensemble. For sufficiently low CDFs, the valid
discrete value is returned instead of a missing value.
Fixes bug when combining discrete and continuous when ensemble missing

A non-missing probability value should always be returned when either
the discrete or continuous model returns a missing value. However this
did not happen when a discrete model that does not use the ensemble
(e.g.  DiscreteConst) is combined with a Continuous model that does use
the ensemble. For sufficiently low CDFs, the valid discrete value is
returned instead of a missing value, because the continuous model was not
checked.
Fixes bug in UpdaterPitBased when the recent obs is missing
Allow auxiliary inputs to be loaded from Data

Previously, only inputs specified for the run were allowed to be
used. This is a problem for schemes that need some auxiliary input.
Allow inputs to simulate a delay in when forecasts are available

Forecasts dataset are often only available after a significant delay
after the model runs are initialized. Simulate this by adding a
'initDelay' option. For a given date and time, the input determines
which is the most recently available date and initialization, taking
into account the delay.
Allow the ensemble to be transformed in ContinuousMoments

The ensemble can now be transformed (power, log, etc) before a
distribution is fitted. The distribution is transformed back afterwards.