Populate .disk with trisquel related metadata

config/hooks/set-disk-info.hook.binary

+#!/bin/bash
+
+source config/bootstrap
+
+mkdir -p binary/.disk/
+echo "Trisquel 7.0 \"$LB_DISTRIBUTION\" - Release $LB_ARCHITECTURES ($(date +%Y%m%d))" | sed s/i386/i686/g > binary/.disk/info
+echo http://trisquel.info/wiki/$LB_DISTRIBUTION > binary/.disk/release_notes_url
+touch binary/.disk/base_installable
+echo 'full_cd/single' > binary/.disk/cd_type
+