A way to stop signals

[AndrewGibb]

It seems from #65 that there should be a way for a user to stop signals. When I try to do close(::Signal) I get a warning that I am closing a non-leaf node. When I use fpswhen(Signal(false),25) on a signal which is already running, and has derived signals, the parent signal remains alive. Is there a way to stop an entire "pipeline" of derived signals?
I'm happy to add a paragraph to the documentation, if I can understand what I need to do.

[shashi]

Although you get the warning, the signal should stop updating and all its children too. It now seems alarmist, and I'm up for removing it.

[AndrewGibb]

Well, that would suit me. As long as you're happy that the warning doesn't communicate something which a user might want to act on. From the discussions I've read, it seems that this package has a clear distinction between a user and a developer, and Nodes are hidden more or less entirely from the user. Hence, from a user perspective, a warning about Nodes is somewhat confusing.
Please let me know if you make this change, and I'll add a brief descrition of close() to the docs.

As an aside, thanks for all the work on the new user interface to this package. I had some trouble understanding the previous version, and I have a nice visualisation built which took about half a day with the new one. Great work.

[JobJob]

@AndrewGibb the change is made. I hope close() still works properly. Please let us know.