Revert "Remove useless thread to start and stop dynamic graph"

This reverts commit 924c3013.

Joseph Mirabel authored 6 years ago and olivier stasse committed 6 years ago

* This was trigerring an exception "Duration is out of dual 32-bit
* range"

Deregister the signal formerly added.
Add a mutex system to prevent removing a signal while triggering it,
 to avoid a crash (especially if the topic was listened to).

The old names are kept for now, but will disappear in the
future.

The old names are kept for now, but will disappear in the
future.