Summary: Implemented take attendance for chairs.

AUTHORS.md: Added myself to authors. xD

attendance.js: Grabs the form data and serializes it into JSON; sent via AJAX. Also has some boilerplate code for handling CSRF tokens, since it would not work otherwise.

chairs/templates/take_attendance.html: Template for take_attendance page.

chairs/views.py: Handles the requests for take_attendance. Also checks to make sure the logged-in person has permission to modify those certain delegates.