linaro-media-create speedup

Greets,

As a side project I've created a fairly simple performance improvement for the linaro-media-create tool. Basically the copying of the root_fs happens earlier in the process such that hwpack and a number of other steps are done in parallel and then at the end there's one last rsync to make sure adjusted files, further installed files are correctly copied.

The code is located here : lp:~tom-gall/linaro-image-tools/rsync-speedup

I'm still testing so use with caution.

From what I've been able to accomplish thus far, the 67M

linaro-headless + hwpack sees the following speed up collected with time:

Normal: real 10m0.596s user 2m2.670s sys 0m9.820s

Parallel: real 7m58.790s user 2m3.170s sys 0m11.950s

Feedback gladly accepted,

Regards, Tom