config: factor Obscure and Reveal into its own package

backend/drive/drive.go

@@ -23,6 +23,7 @@ import (
 	"github.com/ncw/rclone/fs"
 	"github.com/ncw/rclone/fs/config"
 	"github.com/ncw/rclone/fs/config/flags"
+	"github.com/ncw/rclone/fs/config/obscure"
 	"github.com/ncw/rclone/fs/fserrors"
 	"github.com/ncw/rclone/fs/fshttp"
 	"github.com/ncw/rclone/fs/hash"
@@ -66,7 +67,7 @@ var (
 		Scopes:       []string{"https://www.googleapis.com/auth/drive"},
 		Endpoint:     google.Endpoint,
 		ClientID:     rcloneClientID,
-		ClientSecret: config.MustReveal(rcloneEncryptedClientSecret),
+		ClientSecret: obscure.MustReveal(rcloneEncryptedClientSecret),
 		RedirectURL:  oauthutil.TitleBarRedirectURL,
 	}
 	mimeTypeToExtension = map[string]string{