allow refreshing of the file browser window, as Pico does

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@2388 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

src/files.c

@@ -2584,6 +2584,11 @@ char *do_browser(char *path, DIR *dir)
 		free_charptrarray(filelist, numents);
 		goto change_browser_directory;
 
+	    /* Refresh the screen. */
+	    case NANO_REFRESH_KEY:
+		total_update();
+		break;
+
 	    /* Go to a specific directory. */
 	    case NANO_GOTOLINE_KEY:
 	    case NANO_GOTOLINE_FKEY: