updated Installation.md with changes from january 2013
updated Installation.md with changes from january 2013

DanielNeugebauer/adhocracy,alkadis/vcv,liqd/adhocracy,phihag/adhocracy,SysTheron/adhocracy,liqd/adhocracy,liqd/adhocracy,liqd/adhocracy,alkadis/vcv,DanielNeugebauer/adhocracy,phihag/adhocracy,phihag/adhocracy,SysTheron/adhocracy,DanielNeugebauer/adhocracy,DanielNeugebauer/adhocracy,phihag/adhocracy,phihag/adhocracy,alkadis/vcv,alkadis/vcv,SysTheron/adhocracy,alkadis/vcv,DanielNeugebauer/adhocracy