Do not advert tech commands (in doc), various minor fixes

v2/cmd/doc.go

@@ -42,6 +42,7 @@ Please, provide the '-p' flag with a path to define where to put the generated f
 
 Also note that this command also generates the yaml files that we use for pydio.com documentation format.
 `,
+	Hidden: true,
 	Run: func(cmd *cobra.Command, args []string) {
 
 		if docPath == "" {

v2/cmd/files_ls.go

@@ -121,7 +121,11 @@ Note that you can only use *one* of the three above flags at a time.
 			log.Fatal(err)
 		}
 
-		_, exists := rest.StatNode(p)
+		var exists bool
+		if p != "" {
+			_, exists = rest.StatNode(p)
+		}
+
 		if lsExists {
 			// Only check existence and return
 			cmd.Println(exists)

v2/cmd/update.go

@@ -11,7 +11,6 @@ import (
 	"github.com/fatih/color"
 	"github.com/olekukonko/tablewriter"
 	"github.com/spf13/cobra"
-	"go.uber.org/zap"
 
 	"github.com/pydio/cells-client/v2/rest"
 )
@@ -29,7 +28,7 @@ To apply the actual update, re-run the command with a --version parameter.
 
 		binaries, e := rest.LoadUpdates(context.Background())
 		if e != nil {
-			log.Fatal("Cannot retrieve available updates", zap.Error(e))
+			log.Fatalf("Cannot retrieve available updates: %s", e.Error())
 		}
 		if len(binaries) == 0 {
 			c := color.New(color.FgRed)