Openflow controller abstract connector

	- Add openflow_conn abstract impletation for all openflow connectors
	- Refactor all existing conenctor to Inherit la clase abstracta
	- Now all of connector raise an exeption in case of faliure
	- As OF_connector raise an expection, all code that make use of this class now capture the execption.
	- Add to ofc DB table last_error and status column
 	- Check for each operation if an error exist an update DB ofc status and last error column info

Change-Id: Ia3d3bf63fee79dd18d61aeeb08a983dfcb88b729
Signed-off-by: mirabal <leonardo.mirabal@altran.com>
diff --git a/ovim.py b/ovim.py
index cc223a6..06ee50a 100644
--- a/ovim.py
+++ b/ovim.py
@@ -42,6 +42,7 @@
 import openflow_thread as oft
 from netaddr import IPNetwork
 from jsonschema import validate as js_v, exceptions as js_e
+import openflow_conn
 
 HTTP_Bad_Request =          400
 HTTP_Unauthorized =         401
@@ -342,8 +343,9 @@
 
         try:
             if self.of_test_mode:
-                return oft.of_test_connector({"name": db_config['type'], "dpid": db_config['dpid'],
-                                              "of_debug": self.config['log_level_of']})
+                return openflow_conn.OfTestConnector({"name": db_config['type'],
+                                                      "dpid": db_config['dpid'],
+                                                      "of_debug": self.config['log_level_of']})
             temp_dict = {}
 
             if db_config: