Extra ammo consumed at instance schedule finish

[skipor]

Instance takes ammo before schedule token take, that allows be ready, when take next schedule token, and operate close to schedule.
But in case of individual schedules, extra ammo will be taken.

Propose add IsFinished() bool schedule method, that allows check is schedule finished before taking ammo.

In such case, in case of shared schedule, some extra ammos can be consumed anyway at schedule finish, but that is minor problem - that will happen once after shooting finish.

[skipor]

Maybe better will be add EventsLeft() (n int) where
0 - finished
n > 0 - exactly n
n < 0 - don't know, but not finished yet (unlimited, not implemented, etc.)

Such info will be useful to log in every second status.

Also FinishTime() time.Time may be useful for log too.