Small bug with request_reset()

[timbit123]

When we are trying to render a second video, we are creating a new system object and also just the be safe, we are also calling request_reset() but the reset is only called after the first frame is created (during feed_frame)

The issue is that data::frame::next_id_ was not reset to 0 before de creation of the first frame in create_monocular_frame

we are manually resetting it, but I would suggest maybe adding something to reset the value during the system constructor?

Thank you
Tim

[ymd-stella]

Essentially, data::frame::next_id_ designed to be static seems to obscure handling of initialization and destruction. I'll see if I can move it to system::next_id_. Thanks for the report.

[ymd-stella]

Done. #570

we can reset next_frame_id_ to 0 by destroying system.

In addition, reset() will not set next_frame_id_ to 0 after this change. I removed this feature because I thought it was unnecessary and confusing, but if you need it, please let me know.