Remove casper hook and include casper.conf inside chroot

config/hooks/casper.hook.chroot → config/includes.chroot/etc/casper.conf

-#!/bin/bash
-cat << EOF > /etc/casper.conf
 export USERNAME="trisquel"
 export USERFULLNAME="trisquel"
 export HOST="trisquel"
 export BUILD_SYSTEM="Ubuntu"
-export FLAVOUR="Ubuntu"
-EOF
+export FLAVOUR="Trisquel"
+