Replace underscore by lodash (or better: ES6)
Replace socket.io by Websockets ( https://www.npmjs.com/package/websocket )

time per question (in mode "one question at a time" from server...)
compute grades after exam (in teacher's view)
factorize redundant code in course.js, monitor.js and (TOWRITE) grade.js
  (showing students list + grades or papers)
monitoring: main teacher should not be asked for pwd, and button "send feedback" hidden for others

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TODO: format général TXT: (compilé en JSON)

10 (time)
1 (fixed)
Introduction (multiline, from third line ; \n --> <br>)

[Intro q1, multiline]

q1 txt

answer q1 (multiline txt)

q2 intro (multiline)

  q2.1 [intro optional]

	q2.1 txt

	q2.1 options:
	+ good
	- bad
	- bad ...etc

	answer (integer array, one line)

  q2.2 [intro optional]

	q2.2 txt

	answer (html multiline)

Conclusion (last block)

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Seems that GUI would be easier, then summary in YAML file + parse from YAML