Idea taken from meta-virt
Add a new class, sanity-meta-gnome.bbclass, to check for whether necessary
settings are available for bbappend files in this layer to be effective,
and warn users if not.
In addition, a variable SKIP_SANITY_BBAPPEND_CHECK is added to enable users
to explicitly skip the checking to avoid unwanted warnings.
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Armin Kuster
Martin Jansa