Clean up spacing and add comments to clarify difference between base, full and
default models.
Not having spacing around the model definitions in gen-features.c is
particularly frustrating as the reader tends to misinterpret which model they
are looking at or editing.
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>