Add comment regarding accounting error

pyfpdb/Hand.py

@@ -1441,6 +1441,10 @@ class Pot(object):
 
         # Return any uncalled bet.
         committed = sorted([ (v,k) for (k,v) in self.committed.items()])
+        #ERROR below. lastbet is correct in most cases, but wrong when 
+        #             additional money is committed to the pot in cash games
+        #             due to an additional sb being posted. (Speculate that
+        #             posting sb+bb is also potentially wrong)
         lastbet = committed[-1][0] - committed[-2][0]
         if lastbet > 0: # uncalled
             returnto = committed[-1][1]