Tree view improvements

hyrax/app/assets/images/jstree/32px.png

hyrax/app/assets/images/jstree/40px.png

hyrax/app/assets/images/jstree/throbber.gif

hyrax/app/assets/javascripts/jstree.min.js

hyrax/app/assets/javascripts/jstree_init.js

hyrax/app/assets/stylesheets/application.css

hyrax/app/assets/stylesheets/jstree.scss

...x/app/views/hyrax/crc_datasets/_experiment_items.html.erb

hyrax/app/views/hyrax/crc_datasets/_modality_items.html.erb

...views/hyrax/crc_datasets/complex_modalities/show.html.erb

...p/views/hyrax/crc_datasets/complex_sessions/show.html.erb

...p/views/hyrax/crc_datasets/complex_subjects/show.html.erb