Merge "Issue in flow programming: Add a flow, uninstall it, try to remove it. Remove...

Merge "Issue in flow programming: 	Add a flow, uninstall it, try to remove it. Remove seems to fail from gui behavior. 	Try to install the flow. It will fail and uncaught exception in forwardingrulesmanager is printed. Fix: 	Handle invalid flow status toggle request in forwardingrulesmanager. 	IForwardingrulesmanager to exposed a per node and per flow name api for toggling the flow status. 	Flow.web to evaluate api return status by status code and not by status description, 	because a Status with StatusCode.SUCCESS does not imply the description is "Success"."