center OK
Merge pull request #16 from Matthieuuuu/center-flash-msg

center OK
lot if little things, sorry for the big commit
modify the nav in fx of the sign method
Merge pull request #17 from Matthieuuuu/navbar-display-if-logged

modify the nav in fx of the sign method
landing
Merge pull request #18 from Matthieuuuu/landing

Landing : so good
pre-navbar
Merge pull request #20 from Matthieuuuu/navbar-display-if-logged

pre-navbar
fixing conflicts
nothing to see here