Get rid of fakeroot state files, fix fakechroot

The version of fakechroot that comes with ubuntu 14.04 has a dodgy
environment file for chroot /etc/fakechroot/chroot.env which segfaults.
explicitly setting it to debootstrap.env to avoid the segfault. Also
if you specify the state file, it will fail with checksum errors during
apt-get update.

this change will give us Ubuntu 14.04 compatibility