conf/local.conf: Add meta-yocto includes for get distro information
(distro aliases, maintainers, upstream {regex, tracking}) needed by
rrs.
scripts/update.py: Add support for rrs, ability to download poky layer
and set BBPATH to support meta-yocto includes in bitbake.
scripts/rrs_update/*: Modules for update data needed by rrs, distros,
maintainers, upgrades and upstream.
Signed-off-by: Aníbal Limón <anibal.limon@linux.intel.com>