Use default timeouts

Extended a couple of timeouts and changed several tests to
use the default timeout from the configuration parameters
diff --git a/tests/flow_query.py b/tests/flow_query.py
index bad4749..63e6cb5 100644
--- a/tests/flow_query.py
+++ b/tests/flow_query.py
@@ -1371,7 +1371,7 @@
         # </TBD>
         n = 0
         while True:
-            (resp, pkt) = self.controller.poll(ofp.OFPT_STATS_REPLY, 4)
+            (resp, pkt) = self.controller.poll(ofp.OFPT_STATS_REPLY)
             if resp is None:
                 return False            # Did not get expected response
             if n == 0:
@@ -1429,7 +1429,7 @@
 
     def barrier(self):
         barrier = message.barrier_request()
-        (resp, pkt) = self.controller.transact(barrier, 20)
+        (resp, pkt) = self.controller.transact(barrier, 30)
         return (resp is not None)
 
     def errors_verify(self, num_exp, type = 0, code = 0):