update README to not suggest that systemd works without procfs
Ensure unit is journaled for short-lived or oneshot processes

In the time it takes to process incoming log messages, the process we
are logging details for may exit. This means the cgroup data is no
longer available from '/proc'. Unfortunately, the way the code was
structured before, we never log _SYSTEMD_UNIT if we don't have this
cgroup information.

Add an else if case that allows the passed in unit_id to be logged even
if we couldn't capture cgroup information. This ensures a command like
`journalctl -u run-XXX` will return all log messages from a oneshot
process.
Bring bootchart code in line with CODING_STYLE

Use double and not float, as there is little to no benefit.
test: fix TEST-02-CRYPTSETUP

missing generate_module_dependencies call which prevents dm_mod and
dm_crypt modules to be loaded
test: rework run_qemu

It tries to find a suitable QEMU binary and will use KVM if present.
We can now configure QEMU from outside with 4 variables :
  - $QEMU_BIN : path to QEMU's binary
  - $KERNEL_APPEND : arguments appended to kernel cmdline
  - $KERNEL_BIN : path to a kernel
    Default /boot/vmlinuz-$KERNEL_VER
  - $INITRD : path to an initramfs
    Default /boot/initramfs-${KERNEL_VER}.img
  - $QEMU_SMP : number of CPU simulated by QEMU.
    Default 1

(from Alexander Graf's script: http://www.spinics.net/lists/kvm/msg72389.html)
test: wrap $LOOPDEV in quotes

Otherwise things go awry if it is not set ('[ -b ]' is not the same as '[ -b "" ]'!).