Renamed BurnishSpecifier properties. CHANGE.

OLD:

    BurnishSpecifier.lefts
    BurnishSpecifier.rights
    BurnishSpecifier.middles
    BurnishSpecifier.left_lenths
    BurnishSpecifier.right_lengths

NEW:

    BurnishSpecifier.left_classes
    BurnishSpecifier.right_classes
    BurnishSpecifier.middle_classes
    BurnishSpecifier.left_counts
    BurnishSpecifier.right_counts

Current scores should be changed.

CHANGE: should be noted in the 2.16 change log.