Allow emission reset of particles.

[NemesisMate]

There is no current way to reset the particle emission to it start state, at least for it "life". If an emission life is set (eg: 5sec), it will only be visible for the first 5 seconds since the model was open. A way of re-emitting them would be helpful (eg: a button to restart the emitter).

[Aliaksandr Brui]

Added the action in the version 0.9.8