[9fans] replacing sources

[geoff]

I plan to replace sources with haggis (which will take the name
sources) during the afternoon of Tuesday, Sept. 8th.  I will take a
final dump of sources, shut it down, change the dns, initialise
haggis's sources fossil from source's final dump score, and bring
haggis up as the new sources.  This should yield a newer and more
reliable sources machine that is also a little easier to administer.