use hal-lock to prevent automount of make-live-device.sh target

from hal-lock man page:

--8<--
NOTES
       This program is only useful for launching software that doesn’t use HAL at all (since such software launched using hal-lock would be locked out itself); for example a partition table editor part-foo may use wrapper script like this
       hal-lock --interface org.freedesktop.Hal.Device.Storage --exclusive --run /path/to/part-foo-program
--8<--

Thinking, it should be possible for the script to do something clever and get hal-lock to call it itself with an additional argument like --I-certify-that-I-have-a-lock-on-hal-device-storage - would be maybe nicer than having to have two script files, but the logic would be hairier.

I will run some tests to see if hal-lock actually does do what is required.

tested briefly from an xterm in a running liveUSB generating another liveUSB using an .iso file from the local hard drive, some small "not quite perfect" bits still:

1. there is a graphical popup with a close button saying live-rw could not be mounted due to being locked
2. when the script is finished the main partition is mounted on /media/puredyne and a window opens in the xfce4 file manager

see attached bzr diff

Seems to be a tricky problem, see also: http://www.chiark.greenend.org.uk/ucgi/~cjwatson/blosxom/ubuntu/2008-04-12-desktop-automount-pain.html

It seems that in Lucid hald might not be always be running so hal-lock might fail (?), so yet more logic is probably needed to detect hald and only then run hal-lock.

----8<----
ubiquity (2.1.7) lucid; urgency=low
  ...
  * Only run hal-lock if hald is actually running due to changes in
    hal 0.5.14-0ubuntu2.
  ...
----8<----

http://www.ubuntu.com/testing/lucid/beta1#HAL%20removal "hald removed from boot process."

our script seems to be mostly used by us, as people tend to use this GUI stuff, forgot the name. We can live without user-friendliness, marking as won't fix.