Base::prepareFileName

protected function prepareFileName($fileName)
{
	// normalize slashes
	$fileName = Path::normalize($fileName);
	if (mb_substr($fileName, -mb_strlen(self::FILE_EXT)) != self::FILE_EXT)
	{
		$fileName .= self::FILE_EXT;
	}
	
	// convert words delimiter, google dont't like '_''
	$fileName = str_replace('_', '-', $fileName);
	
	return $fileName;
}