- Added option to override recent change to flow_msg_install() which
  default to True for the new clear table parameter retrieve from the
  test config. Still need the option to make a clear-table optional
  on a per-testcase basis.

  It didn't look like this was easy to do without affecting the test-params
  inherited later, so I just added the override option back in.
diff --git a/tests/testutils.py b/tests/testutils.py
index 221fc67..0a6c4bd 100644
--- a/tests/testutils.py
+++ b/tests/testutils.py
@@ -455,7 +455,7 @@
 
     return request
 
-def flow_msg_install(parent, request):
+def flow_msg_install(parent, request, clear_table_override=None):
     """
     Install a flow mod message in the switch
 
@@ -465,7 +465,10 @@
     """
 
     clear_table = test_param_get(parent.config, 'clear_table', default=True)
-    if clear_table:
+    if(clear_table_override != None):
+        clear_table = clear_table_override
+
+    if clear_table: 
         parent.logger.debug("Clear flow table")
         rc = delete_all_flows(parent.controller, parent.logger)
         parent.assertEqual(rc, 0, "Failed to delete all flows")