rewrite logging in console (#788)

- enhance logging throughout the codebase
- all packages at pkg/ should never log
  or perform log.Fatal() instead packages
  should return errors through functions.
- simplified various user, group mapping
  and removed redundant functions.
- deprecate older flags like --tls-certificate
  --tls-key and --tls-ca as we do not use
  them anymore, keep them for backward compatibility
  for some time.

restapi/admin_parity.go

@@ -18,7 +18,6 @@ package restapi
 
 import (
 	"fmt"
-	"log"
 
 	"github.com/minio/console/pkg/utils"
 
@@ -53,9 +52,8 @@ func getParityResponse(params admin_api.GetParityParams) (models.ParityResponse,
 	disksPerNode := params.DisksPerNode
 
 	parityValues, err := GetParityInfo(nodes, disksPerNode)
-
 	if err != nil {
-		log.Println("error getting parity info:", err)
+		LogError("error getting parity info: %v", err)
 		return nil, prepareError(err)
 	}