Get rid of fakeroot state files, fix fakechroot

Fix bad usage:
  fakechroot should always be the first, and fakeroot should follow it
Workaround dodgy environment file:
  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.
Get rid of state files:
  If you specify the state file, it will fail with checksum errors
  during apt-get update, so not specifying that as well.
Use a UK mirror:
  Use a UK mirror to debootstrap the environment.

this change will give us Ubuntu 14.04 compatibility