When we built the Stack Overflow demo, we used intermediate nodes as versions, and attached timestamp to the nodes. We could then sort these nodes by decr timestamp, picking the first one gave us the latest version of the data.
You could do something similar to that. The idea being, instead of connecting text directly to node X, have a node Y in between. So, X --> Y --> "text". Also, Y --> edit timestamp, to allow sorting of Ys, to find the latest one / control the versioning.