getFlatDataFromTree import - conflicts from multiple updates

Hi guys.

This is a great utility your team has tacked onto the project. Thank you.

I'm reading and writing the tree from/to a relational database. I've got a requirement to allow more than one administrator to save the modified tree to the database. (I've also got users who won't be able to modify the tree.)

For the administrators, I'm wondering if there's a way to cleanly allow more than one administrator at a time to make tree edits "out-of-box" with `getFlatDataFromTree`. If not, what I might do is implement a "check-out" facility for certain parts of the tree hierarchy.