Finally! N-Level Branching

Only now have I finally implemented n-level branching (i.e. deep copies)--and it was a lot harder than I had thought, at each and every step of the way.

Found a lot of bugs in the process, so overall it was a good thing. And the latest version of the API (updated to SVN but not yet released) is quite interesting as transactions can navigate from index to index (using the setIndex method). Also, if you want to abort a transaction, you just throw the AbortException.

So what's next? Looks like it is time to implement b-trees. I expect this will not take anywhere near the time it took to implement n-level branching!