Assign a set of importance factors for goodness functions

[petteripitkanen]

The companionship algorithm (shared/companionship.js) calculates a score for the given set of crops in two steps: first the compatibility of the crops is determined, and if the crops are compatible, then the actual score is calculated.

The score is a sum of different goodness values. Each goodness function is assigned an importance factor that specifies how important it is in relation to other goodness values.

We should decide which features are more important than others and assign the importance factors based on that. Roughly speaking the importance factors should be biased towards food production.