NpsBackup class

NpsBackup用于数据备份，导出的数据格式为Sqlite 3.6格式，编码为UTF-8编码。

样例代码：
以下代码演示了如何进行定时数据备份，并通过邮件发送。
var backup_agent = new NpsBackup();
var dmp_file = null;
try
{
     dmp_file = backup_agent.Dump(session.GetSite("your site id"));
     var email = new NpsSmtp("your host",25);
     email.SetCharset('UTF-8');
     email.Connect("your email address","your password");
     email.SetFrom('youremail@email.com');
     email.AddTo('youremail@email.com');
     email.SetSubject('NPS Dump Data ' + new Date());
     email.SetHtmlMsg('');
     email.AddAttach(dmmp_file);
     email.Send();
}
catch(e)
{
     out.Error(e);
}
finally
{
     if(dmp_file!=null) dmp_file.Delete();
}