update firebase/firebase.d.ts to version 2.0.2

Is good, but I need to fix firebase-simplelogin.d.ts and angularfire.d.ts also to change the Firebase to the IFirebase, because these has the following error:
> TS 2304 error: Cannot find name 'Firebase'.

or propose Foo to instead of IFoo naming conventions.
> Naming Conventions
> In general, do not prefix interfaces with I (e.g. IColor). Because the concept of an interface in TypeScript is much more broad than in C# or Java, the IFoo naming convention is not broadly useful.

https://typescript.codeplex.com/WikiPage?title=writing%20Definition%20%28.d.TS%29%20Files