When polygon hit is old age, still reports update age to scripts as zero

[Dunbaratu]

UpdateAge is only being used for PQS hits, even though polygon raycast hits can also be older than 0.

2 fix possibilites:
1 - maybe we don't need the old raycast age code anymore now with Unity5 changes.
2 - if we still do, then move UpdateAge out of LaserPQSUtil into LaserDist where it can be used for both types of old hit.