[tex-live] Restructuring

[Karl Berry]

    Until now, I could just generate the archive from the Master tree.

Fabrice suggested to me that it might be possible to have the current
multiple-tree setup for the TeX Live sources (i.e., what's in p4), but
that the install process would merge them back together into one tree.

Then, I think you could download from the installed tree (which we'd
make available somewhere/somehow) as you did before.

Does that sound workable (both of you)?