Let each package-specific rootfs implementation provide basic functions
to query the existence of a package and install a list of packages and
then have a generic install function so this logic is in one place.
Note: unlike previous versions of this code in OE-Core this uses the
IMAGE_LINGUAS variable and not IMAGE_LOCALES - note that IMAGE_LINGUAS
was what was used in OE-Classic and it is already used in OE-Core in
order to install locale-base-*. This will mean that if IMAGE_LINGUAS is
left at the default you will now get more packages installed. If you
don't want these language support packages then you should set
IMAGE_LINGUAS explicitly.
This restores locale installation to the same state as OE-Classic, only
we now support all the packaging backends.
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
