[Bug Report]canEditTable.vue中v-model如果绑定的值是对象的值,而非对象本身，则v-model无法watch到，从而无法实现双向绑定

### Environment
mac10.12.6 vue2.5.13 iview 2.8.0

### Reproduction link
[http://sorry.ihaveno.com](http://sorry.ihaveno.com)

### Steps to reproduce
views/tables/components/canEditTables.vue结尾watch的代码
watch: {
value (data) {
this.init();
}
}
当引用
此处可以监听
当引用
此处将无法监听改变,暂时用下面代码实现v-model刷新
let _ = my.table
my.table = [];
setTimeOut(()=>{
my.table = _
},1)
备注：canEditTables直接用table组件，以上问题不出现。

### What is expected?
监听失效

### What is actually happening?
监听有效

---
感谢作者，框架开发效率有很大帮助，希望官方提供打赏的二维码，聊表心意：）

Start with views/tables/components/canEditTables.vue and inspect the value watcher near the end of the component. Reproduce the difference between v-model="table" and v-model="my.table" using the linked example or a local Vue 2.5.13 setup. Done means nested object-property bindings update the component as expected, with coverage or a verified reproduction for both binding forms.

Written by the indexing model from the issue text.