Thanks to Sbgodin for his work on Shaarli and Leed, which I adapted.
Please note that if you already have a working instance of BouffeATUlm,
you have to update manually your database. You have to set a new field
for User database (at the end of the database). This field has to be
called "stay_signed_in_token" and to be VARCHAR(32).
Corrected some bugs in User class, related to email management. Added a
sendmail function (usage to be done) and small bug fixes in install and
settings.
