some of the continued work on h2_vs_hs2 was done in the old prepost instead of the new wetb: updated plots, more comparison cases

Conflicts:
	wetb/__init__.py

Prepost

Merging the prepost module into the toolbox. Some aspects in dlc.high_level need to re-evaluated at a later stage: the year and k_shape parameters should be part of the dlc post processing configuration file.

See merge request !1