Crop: method to return hash of sunniness values.
Show sunniness frequencies on crop page

Also cleaned up tests that were relying on the default planting factory
to have a sunniness value set.
Crop: method to return hash of planted_from frequencies

Also tidied up tests which relied on the default planting factory having
a planted_from value set.
Show planted_from frequencies on crop page.
need to test sunniness/planted_from.blank?
Merge branch 'sun_shade_metadata' of https://github.com/Skud/growstuff into Skud-sun_shade_metadata
minor wording changes
Merge branch 'dev' of https://github.com/Growstuff/growstuff into dev

Conflicts:
	spec/views/crops/show.html.haml_spec.rb
Merge branch 'contrib-guidelines' of https://github.com/Skud/growstuff into Skud-contrib-guidelines