Merge branch 'master' into upload-learning-object

app/assets/images/animation.png

app/assets/images/audio.png

app/assets/images/game.png

app/assets/images/image.png

app/assets/images/link.png

app/assets/images/simulator.png

app/assets/images/software.png

app/assets/images/text.png

app/assets/images/video.png

app/assets/stylesheets/application/learning_objects.scss

app/builders/bookmarks_builder.rb

app/builders/builder.rb

app/builders/collection_builder.rb

app/builders/user_builder.rb

app/controllers/collections_controller.rb

app/controllers/learning_objects_controller.rb

app/helpers/learning_objects_helper.rb

app/models/bookmarks.rb

app/models/learning_object.rb

app/models/user.rb