Resolve "Implement general perturbation actions" (!7) · Merge requests · Utopia / models / Evo-Eco Models

This MR ...

… adds perturbation actions that allow changing a certain species' parameters (not the interaction parameters, though)
… adds performance improvements
- by reducing repetitive computations in the update of the functional response
- by using an analytical expression for feeding range overlap breaking change
… sets default speedup to 100 to more closely resemble original model configuration
… fixes a bug where biomass density could become negative if the parent species was chosen to be very small

This is partly motivated by observations from the original model code, see $43 and 210127-Allhoff2015-original-implementation.

Edited Jan 29, 2021 by Yunus Sevinchan

Resolve "Implement general perturbation actions"