`var o Ormer`
定义一个全局的ormer,要导入什么吗,beego会报错`undefined: Ormer`
刚开始看go和beego不清楚情况啊...
```
import "github.com/astaxie/beego/orm"
var o orm.Ormer
```
```
import . "github.com/astaxie/beego/orm"
var o Ormer
```
#2