Incorrect value output in combo of WDL and non-WDL nets

[dje-dev]

As reported by jjosh, for example with T60 + T40.

Circa line 141 of NNEvaluatorLinearCombo, they have different representations that can't be mathematically averaged. Need to find an appropriate transformation, will probably have to add logic to "downgrade" the combination to be non-WDL.