some functions that work in the CDFTOOLS-4.0 build give floating point overflows when built under scitools

[DaveStorkey]

Some functions in this repository give floating point overflow errors when built under the current version of the scitools modules. The same functions work when built from the CDFTOOLS-4.0 release using the old bespoke module set. Perhaps something to do with the linked netcdf library??

This behaviour has so far been found for cdfeke and cdfpsi. Some functions are OK, eg. cdf_xtrac_brokenline,