CaloClusterCorrection+CaloRec: Work around spurious zeros in rfac-v5.

The rfac-v5 interpolation tables contain a couple spurious zeros. This will cause the rfac correction to blow up in the immediate vicinity of these points; a FPE has also been observed when a cluster exactly hits the zero point.

We don't want to put a new version in the databases at this point. Instead, work around by replacing zeros in the rfac interpolation table with an average of adjacent points.

Generate dictionaries for some of the interfaces defined in CaloRec, for use by tests.