Age is not resetting when particle is reused

[bodymovin]

Hi, I think that age should be reset when the reset method on particles is called. If you agre I can do a PR https://github.com/a-jie/Proton/blob/0d2b743d60b9ffa63b43db4dfcfa41288e90de7e/src/behaviour/Behaviour.js#L51

[drawcall]

Very good idea, but I remember that it cannot be modified here. I am very sorry that I am using Flutter now. When I have time, I must take a good look here.

https://github.com/a-jie/Proton/blob/0eef740f626e4fb22e5287d9795a41f41c9e3bcd/example/behaviour/force/force.html