Lint warning when calling static methods on subclasses

We should consider having `Es6ToEs3Converter` add `@deprecated` to any static methods copied from base class to subclass, so that the following produces a lint warning:

``` js
class Base { static foo() {} }
class Sub extends Base {}
Sub.foo();
```

Start by tracing Es6ToEs3Converter and the handling of static methods copied from a base class to a subclass. Use the JavaScript example in the issue as the reproduction; the work is done when calling Sub.foo() produces the intended lint warning.

Written by the indexing model from the issue text.