Fixed: accept-buildout-test-releases defaulted to true.

       (This was an ill-considered temporary attempt to
       make used of the new bootstrap script easier.)

Moved the download locatiion to downloads.buildout.org.

bootstrap/bootstrap.py

@@ -40,7 +40,7 @@ parser.add_option("-v", "--version", help="use a specific zc.buildout version")
 
 parser.add_option("-t", "--accept-buildout-test-releases",
                   dest='accept_buildout_test_releases',
-                  action="store_true", default=True,
+                  action="store_true", default=False,
                   help=("Normally, if you do not specify a --version, the "
                         "bootstrap script and buildout gets the newest "
                         "*final* versions of zc.buildout and its recipes and "
@@ -98,7 +98,7 @@ cmd = [sys.executable, '-c',
 find_links = os.environ.get(
     'bootstrap-testing-find-links',
     options.find_links or
-    ('https://github.com/buildout/buildout/downloads'
+    ('http://downloads.buildout.org/'
      if options.accept_buildout_test_releases else None)
     )
 if find_links: