User: +gender

Add field gender to user table + request it at registration (together with languages & birthyear)

Field = Gender Question + Radio or dropdown

Êtes-vous...: Une femme[=Female]/Un homme[=Male]/Autre[=Other]/Je préfère ne pas le dire[=NA] Are you...: A woman[=Female]/A man[=Male]/Other/Prefer not to say[=NA]

added To do label

changed the description

assigned to @bridubois

added To review label and removed To do label

closed

changed milestone to %0.1: Basic test & chat ready

removed To review label