WordPress Plugin Localization
My mistake was on language files path declaration.
this fixed:
$plugin_path = dirname( plugin_basename( __FILE__ ) ) . '/languages/';this was wrong:
$plugin_path = dirname(plugin_basename( __FILE__ ) .'/languages' );I was answered on Wordpress Stack Exchange
Contrary to my previous statement, I've succeeded using this filename: gallery-view-for-wp-it_IT.mo
Strange, though - themes use just it_IT.mo.