Updated bird tour experiment. Added background images, recording information about selected species.

modified:   public/experiment_assets/bird_tour.json
new file:   public/experiment_assets/bird_tour/Arid Grasslands.jpg
new file:   public/experiment_assets/bird_tour/Coastal Heathland.jpg
new file:   public/experiment_assets/bird_tour/Dry Sclerophyll Forest.jpg
Added bird_tour_counts.json to record counts. Still adding javascript to get it to work.

modified:   app/assets/javascripts/angular/controllers/experiments.js
modified:   app/assets/templates/tour_experiment.html
modified:   public/experiment_assets/bird_tour.json
new file:   public/experiment_assets/bird_tour_counts.json