Disabled extrapolation and softened parsing.
Disabled extrapolation and softened parsing.

The cubic spline interpolator no longer extrapolates beyond the
available frequencies. Instead, NaNs are returned at points outside
the frequency band. Its unclear what havoc this will cause downstream
in processing (i.e., the full chain has not yet been tested) but this
move disables extrapolation.

Many of the newest EMTFs added to SPUDS are not as strict in naming
conventions, e.g., using ZXX in the Zxx section. Made a one liner
change to be less sensitive about case mismatches.

butala/pyrsss