create_ktis_at_edges now operates correctly with None-ended slices.
create_kpv_from_slices needed the slices sorted to make the later index computation work correctly.
node now creates kpv at upper bounds of a range of slices for create_kpv_from_slices. Essential for fuel calculations where integrals always increase to maximum values.
classes OnBlocks, OffBlocks and APURunning added to support fuel KPVs.