parc update to atlas hiearachy and annotations
parc update to atlas hiearachy and annotations

Individual labels will not have isDefinedBy, only the root label will
have isDefinedBy. This ends up providing a more accurate picture of how
labels are defined for paxinos. The exact literals that are used per
atlas version are handled as annotations. The intersection between
atlas version and the labels will be handled by regions as needed.
This way the labels are kept orthogonal from their geometric
represetation in any given atlas.

tgbugs/pyontutils,tgbugs/pyontutils,tgbugs/pyontutils,tgbugs/pyontutils