Allow BerlekeyDB up through 4.7.  I doubt any of our unixy buildbots even have
that installed yet but the module code supports it.
diff --git a/setup.py b/setup.py
index 8ed4486..c8cbbcc 100644
--- a/setup.py
+++ b/setup.py
@@ -687,10 +687,7 @@
         # a release.  Most open source OSes come with one or more
         # versions of BerkeleyDB already installed.
 
-        max_db_ver = (4, 5)  # XXX(gregory.p.smith): 4.6 "works" but seems to
-                             # have issues on many platforms.  I've temporarily
-                             # disabled 4.6 to see what the odd platform
-                             # buildbots say.
+        max_db_ver = (4, 7)
         min_db_ver = (3, 3)
         db_setup_debug = False   # verbose debug prints from this script?