new nightly builds setup

[Ben Pfaff]

I've changed how the PSPP nightly builds work.  Now they are
available at:
        http://benpfaff.org/~blp/pspp-master/
        http://benpfaff.org/~blp/pspp-stable/
for the respective branches.  The subdirectories have a lot more
information about the builds now.

For now, you can clone the builder from:
        git://benpfaff.org/pspp
in the "build" branch.  Eventually I'm going to clean it all up
and push it to the Savannah repository.

I'm going to continue improving how this works, but it's already
nicer than it was before.
-- 
"I don't want to learn the constitution and the declaration of
 independence (marvelous poetry though it be) by heart, and worship the
 flag and believe that there is a god and the dollar is its prophet."
--Maarten Wiltink in the Monastery