Small bug fix for avgSMS comparison

  * when combining SRs (datasets), if each dataset theory prediction
    contains a single SMS, an averageSMS is assign to the dataset prediction.
  * when checking if all the averageSMS are the same (so we can assign a single
    SMS to the combination ) the comparison breaks
    if the avgSMS have distinct shapes (canonical names)
  * the fix includes a canonical name comparison to the avgSMS comparison,
    so it works even if the avgSMS have distinct shapes.

smodels/matching/clusterTools.py

@@ -107,6 +107,9 @@ def __cmp__(self, other):
 
         if not isinstance(other, TheorySMS):
             return -1
+
+        if self.canonName != other.canonName:
+            return -1
 
         for nodeIndex in self.nodeIndices:
             nodeA = self.indexToNode(nodeIndex)