Backport r58757, r58758, r58759.
Undoes incorrect dbtables fix and errant strdup introduced as
described below:

r58757 | gregory.p.smith | 2007-11-01 14:08:14 -0700 (Thu, 01 Nov 2007) | 4 lines

Fix bug introduced in revision 58385.  Database keys could no longer
have NULL bytes in them.  Replace the errant strdup with a
malloc+memcpy.  Adds a unit test for the correct behavior.

r58758 | gregory.p.smith | 2007-11-01 14:15:36 -0700 (Thu, 01 Nov 2007) | 3 lines

Undo revision 58533 58534 fixes.  Those were a workaround for
a problem introduced by 58385.

r58759 | gregory.p.smith | 2007-11-01 14:17:47 -0700 (Thu, 01 Nov 2007) | 2 lines

false "fix" undone as correct problem was found and fixed.
diff --git a/Lib/bsddb/dbtables.py b/Lib/bsddb/dbtables.py
index f6c7f02..be2641f 100644
--- a/Lib/bsddb/dbtables.py
+++ b/Lib/bsddb/dbtables.py
@@ -360,12 +360,11 @@
         unique = 0
         while not unique:
             # Generate a random 64-bit row ID string
-            # (note: this code has <64 bits of randomness
+            # (note: might have <64 bits of true randomness
             # but it's plenty for our database id needs!)
-            # We must ensure that no null bytes are in the id value.
             blist = []
             for x in xrange(_rowid_str_len):
-                blist.append(random.randint(1,255))
+                blist.append(random.randint(0,255))
             newid = struct.pack('B'*_rowid_str_len, *blist)
 
             # Guarantee uniqueness by adding this key to the database