* V2 overlay skeleton (#2097)

* skeleton

* basic test

* remove useless files

* remove useles files

* semicolon

* refactoring

* rm useless files

* animation fix

* fix tests

* hide toolbar

* default values

* default values

* tmp commit

* tests

* animated hide

* animated hode improve

* fix topbar

* readme

* lifecycle WIP

* lifecycle alert delay hack

* test fixes

* move topbar to container

* fix tests

* refactor

* refactor WIP

* refactor fix tests

* nav options fallback to parse

* WIP

* topbar background fix

The only argument to `popTo` is the containerId to pop to, not the current containerId as well.  Also showing `this.props.previousContainerIds` lead me to believe that was included automatically (similar to `this.props.containerId`) so I changed that to avoid confusion.

The new path is `.../lib/ios` not just `/ios`

* animation fix

* fix tests

Since the docs suggested we remove everything inside the `didFinishLaunchingWithOptions`, without the return statement there was an `Control reaches end of non-void function` error since the function expects a boolean return. After adding this, the error goes away.

In the list of `LayoutTypes`, `tabs` is not defined, hence this throws an error. Replaced it with `bottomTabs`.