Add custom comparison function

[HyperCrowd]

Tags should not only be Tag objects, but also functions that actively process how Tags are compared and modified

This will allow us to do:

• maxValue
• rough < 3
• !ocean
• lake || river
• doubling & halving: double or halve the default listed odds of a given table entry based on a set of defined tags, doubling or halving for each tag matched (prob. want to calculate total number of doublings/halvings & then execute just one or the other)
• arbitrary tag gating: allow entries to be removed from the entry pool if specified tags are present (i.e. a "nomagic" tag disqualifies magical entries), or if a threshold of presence is reached