The Alternative activity allow students to register to one or several choices,
among a given list.
It can fulfill several purposes: registration for a conference, choice of
a date for an examination, of an internship, etc.
Alternative is similar to the official "Choice" module, but has many settings
to adapt to various needs:
- individual or team registration (with a team leader)
- possible quota on each option
- single choice, or limited/unlimited number of choices
- manual input for the options, or import of a csv file
- csv export of the registrations