Lots of minor bugs fixed

app/create/templates/create_experiment_upload_stimuli.html

app/create/views.py

app/experiment/templates/add_stimuli.html

app/experiment/templates/edit_stimuli.html

app/experiment/templates/view_experiment.html

app/experiment/views.py

app/routes.py

app/static/js/canvas.js

app/static/js/enable_button.js

app/task/templates/task.html

app/task/views.py

create_rating_db.sql

embody_plot.py