Move over code from buildstats-diff to new scripts/lib/buildstats.py
module in order to share code related to buildstats processing. Also,
refactor the code, introducing new classes to make the code readable,
maintainable and easier to debug.
[YOCTO #11381]
(From OE-Core rev: 8a2cd9afc95919737d8e75234e78bbc52e1494a1)
Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
