CDMS3DPlot -> CDMSCell connections are invalid

[remram44]

CDMS3DPlot's 'self' output port has type CDMS3DPlot, but CDMSCell's 'plot' input port has type CDMSPlot.

The connection is built programmatically by the pipeline helper, but it is invalid. A common base CDMSBasePlot should have been introduced (or CDMSPlot renamed to CDMS2DPlot?).

I don't know if we can change this without breaking previously saved workflows, UV-CDAT doesn't use the pipeline upgrades mechanism (and doesn't even version packages).

Everything would be fine if CDMS3DPlot was a subclass of CDMSPlot but it's not.

[doutriaux1]

@remram44 at this point I don't think there are many saved workflows. I think it's ok to break it early, before many people have saved workflows, and make it right.

[doutriaux1]

@remram44 for extreme/desperate cases do you think it would be possible for users to manually edit their workflow to make it work again?