new Folding@home package; please review

[Nick Lewycky <nicholas@mxc.ca>]

The new Folding@home packages are ready! And they've got some great
new features and highly demanded changes:

  * Package renamed to "fahclient-installer" (henceforth,
    "outer package")
  * Actual client software package now named "fahclient"
    ("inner package")
  * Outer package ships with "fahclient-build", a script to download
    and build the inner package.
  * Full man pages. Folding@home documentation has been blessed by
    Vijay Pande himself!
  * Sophisticated "attempt automatic download only if online" code in
    postinst simulates BSD routing in pure POSIX shell and GNU grep!
  * Inner package Build-Depends on outer package.
  * Outer package depends on the union of inner packages' Build-Deps
    and Depends (minus itself).
  * No longer clobbers client.cfg on upgrade.

</marketese>

Actually, writing one package to build another is a lot harder than it 
sounds at first. I'm not one half as confident in the correctness of 
this package as I was of my first submission. That said, I'd really 
appreciate some pointers on what I could do better.

Available at http://wagon.dhs.org/folding/

Thanks,
Nick Lewycky