public static function removeOldFiles() {
		
		if (!is_dir(static::TEMP_FOLDER)) {
			return;
		}
		
		$app = Application::getInstance();
		$counter = 0;

		$files = Utilities::getDirectoryFilenames(static::TEMP_FOLDER);

		foreach ($files as $file) {

			$pathFile	= APPLICATION_PATH . '/' .static::TEMP_FOLDER . '/' . $file;
			$fileLife	= time() - filemtime($pathFile);
			$maxLife	= static::FILE_EXPIRE * 60;
			
			if ($fileLife > $maxLife) {
				$counter++;
				unlink($pathFile);
			}

		}
		
		if ($counter) {
			$app->logEvent($counter . ' files has been deleted from ' . static::TEMP_FOLDER);
		} else {
			$app->logEvent('No old files deleted from ' . static::TEMP_FOLDER);
		}
		
	}