[VOL-2471] Update library to use package logger

This commit consists of the following:
1) Add a GetLogLevel() API to make it easier to use specific
logger.   There is also the V() API that kind of do something
similar.
2) Add a common.go file to some heavily used packages in order
to dynamically set their log level and also to a set a specific
logger per package.
3) Use a per package logger for some of the heavily used packages
for improved performance.

Change-Id: If22a2c82d87d808f305677a2e793f8064f33291e
diff --git a/pkg/adapters/common/events_proxy.go b/pkg/adapters/common/events_proxy.go
index ab6b0d0..ebc9423 100644
--- a/pkg/adapters/common/events_proxy.go
+++ b/pkg/adapters/common/events_proxy.go
@@ -81,7 +81,7 @@
 /* Send out device events*/
 func (ep *EventProxy) SendDeviceEvent(deviceEvent *voltha.DeviceEvent, category adapterif.EventCategory, subCategory adapterif.EventSubCategory, raisedTs int64) error {
 	if deviceEvent == nil {
-		log.Error("Recieved empty device event")
+		logger.Error("Recieved empty device event")
 		return errors.New("Device event nil")
 	}
 	var event voltha.Event
@@ -90,10 +90,10 @@
 	event.Header = ep.getEventHeader(deviceEvent.DeviceEventName, category, subCategory, voltha.EventType_DEVICE_EVENT, raisedTs)
 	event.EventType = &de
 	if err := ep.sendEvent(&event); err != nil {
-		log.Errorw("Failed to send device event to KAFKA bus", log.Fields{"device-event": deviceEvent})
+		logger.Errorw("Failed to send device event to KAFKA bus", log.Fields{"device-event": deviceEvent})
 		return err
 	}
-	log.Infow("Successfully sent device event KAFKA", log.Fields{"Id": event.Header.Id, "Category": event.Header.Category,
+	logger.Infow("Successfully sent device event KAFKA", log.Fields{"Id": event.Header.Id, "Category": event.Header.Category,
 		"SubCategory": event.Header.SubCategory, "Type": event.Header.Type, "TypeVersion": event.Header.TypeVersion,
 		"ReportedTs": event.Header.ReportedTs, "ResourceId": deviceEvent.ResourceId, "Context": deviceEvent.Context,
 		"DeviceEventName": deviceEvent.DeviceEventName})
@@ -105,7 +105,7 @@
 // SendKpiEvent is to send kpi events to voltha.event topic
 func (ep *EventProxy) SendKpiEvent(id string, kpiEvent *voltha.KpiEvent2, category adapterif.EventCategory, subCategory adapterif.EventSubCategory, raisedTs int64) error {
 	if kpiEvent == nil {
-		log.Error("Recieved empty kpi event")
+		logger.Error("Recieved empty kpi event")
 		return errors.New("KPI event nil")
 	}
 	var event voltha.Event
@@ -114,10 +114,10 @@
 	event.Header = ep.getEventHeader(id, category, subCategory, voltha.EventType_KPI_EVENT2, raisedTs)
 	event.EventType = &de
 	if err := ep.sendEvent(&event); err != nil {
-		log.Errorw("Failed to send kpi event to KAFKA bus", log.Fields{"device-event": kpiEvent})
+		logger.Errorw("Failed to send kpi event to KAFKA bus", log.Fields{"device-event": kpiEvent})
 		return err
 	}
-	log.Infow("Successfully sent kpi event to KAFKA", log.Fields{"Id": event.Header.Id, "Category": event.Header.Category,
+	logger.Infow("Successfully sent kpi event to KAFKA", log.Fields{"Id": event.Header.Id, "Category": event.Header.Category,
 		"SubCategory": event.Header.SubCategory, "Type": event.Header.Type, "TypeVersion": event.Header.TypeVersion,
 		"ReportedTs": event.Header.ReportedTs, "KpiEventName": "STATS_EVENT"})
 
@@ -131,7 +131,7 @@
 	if err := ep.kafkaClient.Send(event, &ep.eventTopic); err != nil {
 		return err
 	}
-	log.Debugw("Sent event to kafka", log.Fields{"event": event})
+	logger.Debugw("Sent event to kafka", log.Fields{"event": event})
 
 	return nil
 }