Provide a mechanism for distro comparison update tasks to display
progress. In practice this means the update command needs to write the
progress percentage to a file and then the log view (which is polled by
the frontend) reads this file. Originally I was going to use a FIFO for
this but that turned out to be a but unreliable; I also tried to use
Celery's state mechanism to pass it back but I simply could not get it
to work. The file-based mechanism is good enough though.
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
d063aab917