Additional routing + new functions

modified:   pizza.py
Get data from form correctly

modified:   sessions.py
refactor js files

new file:   static/js/active_sessions.js
modified:   static/js/application.js
modified:   static/js/order_pizza.js
Adds modal to enter user email when joining

modified:   templates/active_sessions.jinja
Adds first pizza place in list, not whole array

modified:   templates/start_session.jinja
Redirects on successfull post of oreder

modified:   static/js/order_pizza.js
Refactor + add review of order view

modified:   pizza.py
new file:   templates/review_order.jinja
Fix saving of order

modified:   sessions.py
Fix broken modal buttons

modified:   static/js/active_sessions.js
modified:   templates/active_sessions.jinja