another small update to collision avoidance/crowd demo
added separate agent controll..

use 1 to add agent 2 to remove agent,its still unmanaged so
not much fps per large group,and theres still an update speed
issue i have to resolve ,i see also theres sometimes a head to head
collision issue aswell ,wil look into it.

i added about 30 agents before my fps dropped to just above 60