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

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. 
