numatune: Encapsulate numatune configuration in order to unify results

numatune: Encapsulate numatune configuration in order to unify results

There were numerous places where numatune configuration (and thus
domain config as well) was changed in different ways.  On some
places this even resulted in persistent domain definition not to be
stable (it would change with daemon's restart).

In order to uniformly change how numatune config is dealt with, all
the internals are now accessible directly only in numatune_conf.c and
outside this file accessors must be used.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>