Added download links for CSV annotation download for details pages on Sites and Projects.

Listed links to audio recordings on site details page.

modified:   Gemfile.lock
modified:   app/assets/javascripts/angular/controllers/home.js
modified:   app/assets/javascripts/angular/controllers/projects.js
modified:   app/assets/javascripts/angular/controllers/sites.js
modified:   app/assets/javascripts/angular/services/services.js
modified:   app/assets/templates/project_details.html
modified:   app/assets/templates/site_details.html
modified:   app/controllers/audio_events_controller.rb
modified:   app/controllers/audio_recordings_controller.rb
modified:   app/serializers/site_serializer.rb
modified:   db/development_seeds.rb