BBB nodes will use octalbonescript if it is available

The BBB nodes now also work with the alternative octalbonescript fork of the original bonescript library https://github.com/theoctal/octalbonescript
This is faster, bug-fixed, version of the bonescript library, almost (but not quite) entirely API compatible with the original. It drops some of the Cloud9 IDE support node-RED does not use.
I have tested with both libraries, but it could always do with a bit more. Note that because the two libraries use different approaches to creating & loading device tree overlays, and these cannot (yet) be reliably unloaded, you have to reboot the BBB when switching from one library to the other.