Refine and optimize the Madingley foraging system

The Madingley foraging system is complicated and contains many functions over three files and two classes. I am reasonably confident that my implementation is accurate to the published equations but another detailed sweep is necessary

After the double-check to make sure the implementation is accurate to the science, we need to see what can be improved. The foraging system was the major computational bottleneck of the original Madingley simulation and we are likely to have the same problem.
We will need to improve:

- naming
- method organization
- computational efficiency

Any thoughts on good ways to do this are encouraged.