Better log output int8, int, int16, int32, int64, float32, float64, bool. (#2258)
Better log output int8, int, int16, int32, int64, float32, float64, bool. (#2258)

* Better log output int, int16, int32, int64, int8, float32, float64.

* Better log output bool

jinzhu/gorm,jinzhu/gorm