rails g scaffold PlantPart...

Also migration to remove the string plant_part.
Load plant parts in db:seed and rake task.
Test that only admins can manage plant parts.
Add friendly URLs to plant parts.
Can't delete plant parts that are being used
plant parts have crops through harvests
remove annoying scaffold-generated tests
prettify plant part views
Add plant parts to harvest views
Show aggregate 'grown from' data on crop page
Added plant part to harvest CSV
Added harvests and plant parts to crops CSV