revset: changed orderedlazyset to also extend _orderedsetmixin

revset: changed orderedlazyset to also extend _orderedsetmixin

Now orderedlazyset can use the lazy min and max implementation.

--- a/mercurial/revset.py	Thu Mar 13 11:36:11 2014 -0700
+++ b/mercurial/revset.py	Thu Mar 13 11:36:45 2014 -0700
@@ -2367,7 +2367,7 @@
     def filter(self, l):
         return lazyset(self, l)
 
-class orderedlazyset(lazyset):
+class orderedlazyset(_orderedsetmixin, lazyset):
     """Subclass of lazyset which subset can be ordered either ascending or
     descendingly
     """