Drop zeros for nonlinear functions

[mcosovic]

Hello,

It would be quite beneficial to incorporate a drop zeros feature akin to the functionality found in affine or quadratic functions.

[pulsipher]

You should refer to the conversations in #3498 and #3502.

[odow]

Thanks for the report, it's really helpful to hear feedback.

I'm going to close this in favor of #3498, but the fact it came up within hours of the release means that we probably need to at least fix the 0.0 + terms that appear.

Let me know if you have any other suggestions.