Changes

Renamed smth_range to heaviside_smth_range

Added tot_vartn_normlzd statistics. Renamed sclr in advance_helper_module to scalar to be more consistent with clubb naming schemes.

Implemented three further normalized variation stats. Included a (most likely temporary) check because in a few cases, denominator for normalization would be 0.

Fixed typo in pyplotgen and fixed display of plotted time (previously displayed on the wrong line).

Dealt with issue https://github.com/larson-group/clubb/issues/985

Changed priorities of total normalized variation stats, included error handling in total normalized variation stats.

Removed duplicate VariableGroupNormalizedVariations.py

Renamed pdf_output_filename. Added grid_level constant to avoid magic numbers in stats_update_var_pt calls.

Gunthers branch 2 (#1002)

* Pushing loop down through advance_windm. Other files needed to be touched because they were using a simple function, xpwp_func, which has been replaced in relevenant places by the few lines of code it takes to do.

* Cleaned up intents

* Moving xpwp calcuations back to procedure, but making procedure a 1/2D interface in advance helper. Other various small tweaks as well.

Bugfix for merge #1000. stderr was not imported in stat_clubb_utilities.F90, causing compilation to fail.