Add helper for setting nested defaults
Add start of an Interactive definition

Right now this is just going to hold the toolbar button
properties. Eventually this should probably help us define
more of the interactive by passing in a simple object,
including the rules, etc.
Move interactive elements to new interactive folder

This allows us to keep the "models" and "views" folder
to be pure agent-model-related classes.
Add addOrganismButtons to toolbar

Currently these don't have images or state-persistance
Merge plant species flower rules
Make it possible to define button images in species
Add button images to varied-plants species
Add button images to AddOrganismButtons