vala.bbclass DEPENDS on vala and vala-native: Drop the inherit so
that these dependencies can be added on-demand based on vte
PACKAGECONFIG. Add relevant items from vala class into the recipe.
Add copy of vapigen.m4 so building without vala actually succeeds.
Make building without vala the default PACKAGECONFIG.
Fixes [YOCTO #10386].
Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
