what should be done to merge nested trees patch to bzr-core?

[Alexander Belchenko]

I've been thinking about nested trees design and implementation since 
we've talked about it last year at Bazaar sprint at La-Hulpe with Marius 
Kruger. I have some new information about scmproj usage and my thoughts 
about how I see nested trees, and I want to share that with the list.

I also have questions about Aaron's nested trees design, but the most 
interesting for me: what is blocked this proposal?

https://code.launchpad.net/~abentley/bzr/nested-trees-composite-tree/+merge/6264