Add a way to propagate signals instead of having to emit a new signal from a handle

[sylbeth]

I'd like to have a way to propagate a signal without needing to write a handler for it. Sometimes, you just need a node to reinterpret a signal as one of their own signals, and that's it. I believe this would lead to performance improvements (albeit quite low) and reduce code clutter, also making it extremely easy to propagate them. I'd give another method instead of connect, being reemit, or something, and thus when receiving the signal reemiting it exactly the same under some other name. node.signal.reemit(node2.signal) could be a good way to do it, and also to give the option to do it from the editor.

[sockeye-d]

You can already do

node.hidden_signal.connect(new_signal.emit)

[sylbeth]

OH, yeah, I was being kind of dumb, and I'm the one that always does this kind of thing instead of making closures in Rust, ha, funny. Thank you very much!