- Ajout d'un editeur de markdown
    - On garde le formattage des espaces
    - On empeche l'utilisateur de mettre du html

(cherry picked from commit 029fcbf4)

	- Also added possibility for the poll's maker to edit this hidden results option.

New files :
* classic_poll.js -> loaded on page choix_autre.php
* date_poll.js -> loaded on page choix_date.ph
* framadatepicker.js -> loaded on pages that need the date picker