- Replace the polynomial fit in `cloud_fraction_from_cloud_factor()` by the analytical inverse of the function in `cloud_factor_from_cloud_fraction()` (0170d6a84569b38c94ea852bca778c79c426ea86)
- Fix for cloudiness method `prescribed`: the prescribed values should be the cloud area fraction (corresponding to the `cloud_fraction` model variable), not the "cloud factor" (ratio of actual to potential radiation) (50e908d09d42ce80a93793f18f25cd8a30a51fcb)
- Consequently, the meteo input variable `cloud_cover` has been renamed to `cloud_fraction` for consistency (however, values are expected to be in percent there, in contrast to the model variable `cloud_fraction` which has fractional values (0-1) (1325f5e3cb701a3a89b92a49bd964156b0d54bfa)