Fix for hanoi store recovery

If we're opening a hanoi store configured with
smaller nursery size than the default, then
we need to make sure that we also open the
small levels.

Future feature is to actually squash the
smaller levels.

src/hanoi.erl

@@ -240,7 +240,7 @@ open_levels(Dir,Options) ->
                              {Level, NextMax}
                      end,
                      {undefined, 0},
-                     lists:seq(MaxLevel, ?TOP_LEVEL, -1)),
+                     lists:seq(MaxLevel, min(?TOP_LEVEL, MinLevel), -1)),
 
     %% we need to do this much merge work before we can guarantee
     %% response times ... this is the amount of "in flight" merging