\hbox{\begin{beamercolorbox}[wd=.15\paperwidth,ht=2.5ex,dp=1.125ex,leftskip=.3cm,rightskip=.3cm plus1fill]{author in head/foot}%
\usebeamerfont{author in head/foot}\insertframenumber{} / \inserttotalframenumber
\end{beamercolorbox}%
\begin{beamercolorbox}[wd=.2\paperwidth,ht=2.5ex,dp=1.125ex,leftskip=.3cm plus1fill,rightskip=.3cm]{author in head/foot}%
\usebeamerfont{author in head/foot}\insertshortauthor
\end{beamercolorbox}%
\begin{beamercolorbox}[wd=.65\paperwidth,ht=2.5ex,dp=1.125ex,leftskip=.3cm,rightskip=.3cm plus1fil]{title in head/foot}%
\usebeamerfont{title in head/foot}\insertshorttitle~--~\insertshortdate
\end{beamercolorbox}}%
\vskip0pt%
}
\usepackage{tabu}
\usepackage{multicol}
\usepackage{vwcol}
\usepackage{stmaryrd}
\usepackage{graphicx}
\usepackage[normalem]{ulem}
\title[Garage : jouer dans la cour des grands quand on est un hébergeur associatif]{Garage : jouer dans la cour des grands \\quand on est un hébergeur associatif}
\subtitle{(ou pourquoi on a décidé de réinventer la roue)}
\author[Q. Dufour \& A. Auvolat]{Quentin Dufour \& Alex Auvolat}