This adresses issue 173: now the window_size can be defined per meteo parameter and per resampling algorithm. The Interpolations1D section's syntax has been changed in order to accomodate the change and enable specifying multiple resampling algorithms in the future. An exception is thrown when using the old syntax (until we would consider that everybody should have migrated). The nearest_neighbour algorithm key has been renamed to n_neighbor. 

Overall, this commits breaks compatibility with previous ini file but the calculated results remain the same after migrating the config files.