Add interface implements annotation

I want use `@interface`,  `@implements {Type}` annotation in my company projects.

these are Google Closure Compiler jsdoc annotations.

i heard that you want add this feature to 3.4.0 but we need this feature 

so i add some codes for this. please check.

thank you.
Google Closure Linter's interface, implements tags are work only prototype functions.
i think initialize prototype property to primitive type is not useful.
consider this.

```javascript
/**
 * @interface
 */
function ILayer() {}
ILayer.prototype.hello = '123' // is this property really useful?
ILayer.prototype.update = function() {};

function MyLayer() {}

// i think this strange, and google closure linter don't check this.
MyLayer.prototype.hello = '123'

MyLayer.prototype.update = function() {
    // update Map Layer codes
};
```

i fix all your comment's excepts "implements not functions".
i don't know you mean this. please comments.