* Add support for react-native 0.52.0

* Refactore a bit

1. Rename `DevCommandsHandlerProxy` to `DevHelperProxy` so it reflects the changes in RN. See d19afc73f5 .
2. Add few comments to show which code is used on `RN >= 0.52` and which on `RN <= 0.51`.

* Now allowing the custom nav bar to take up the whole space on iOS

The custom nav bar on iOS was really just a custom view applied to the title of the navigation bar.
There were problems with this approach, because the navigation bar messes up the frame of the title very frequently, especially when the orientation is changing. That behaviour is accepted when the title is a label, but not when we have a custom component.

With this pull request the custom nav bar component can take up the full width of the navigation bar, no matter what orientation we're at.

* Added mix of native btns and custom component on the Custom TopBar screen of the example project

The initial modal screen got animated twice, this regression was introduced in #2761.

* custom viewController support

* native component support and e2e

* custom viewController support

* native component support and e2e

* unit test fix

* Rename BottomTabOptionsPresenter

* Set currentTabIndex in BottomTabsPresenter

* implement BottomTabs visible

* options

* proof of concept

* pop

* test fix

* default options

* scale

* rotation

* null check

* refactor

* refactor

* refactoring

* fix tests

* Update TopBar docs (animateHide -> animate)

* Update BottomTabs docs (animateHide -> animate)

* Update Navigation.push docs

* docs/installation-android: remove "@Nullable" annotation

* Docs/SideMenu: Add 'center' prop

* Rename TopBar.animateHide to animate

also fix some options in playground app

* Consolidate topBar visibility in childWillDisappear

* Rename BottomTabs.animateHide to animate

* Added bottomTabFontSize and bottomTabSelectedFontSize properties for android tab bar

* Added tabFontSize and selectedTabFontSize properties to the doc

* Fix default values of bottomTabFontSize and bottomTabSelectedFontSize properties.

For example, the following code will start a single screen app with two
screens pushed into the stack.

```js
Navigation.startSingleScreenApp({
    components: [
    {
      screen: 'example.Types',
      title: 'Navigation Types',
      overrideBackPress: true
    },
    {
      screen: 'example.Types.CustomButtonScreen',
      title: 'Custom Buttons'
    }
  ]
});
```

* basic fab

* fab menu

* fab menu clicks

* pop lifecycle

* options lifecycle

* refactoring

* refactor

* parse unit tests

* refacotr

* fix test

* align

* fab unit tests

* more tests

* size

* hide on scroll in progress

* options

* menu collapse

* parser test

* merge v2

* refactor

* refactor

* more refactor

* more refactor

* fix

* more refactoring

* refactor

* refactor

* fix

* fix

* fixed undefined key

* refactor

* refactor

* refactort

* Refactor resetTo view controller creation into function

This will allow for multiple view controllers to call the same function to create their instance.

* Configure resetTo to take multiple components to set view controllers for

This allows for a navigation stack to be recreated with multiple view controllers rather than just one.

* Breakup view controller initializer into multiple lines for legibility

* Hide topBar with animation by default

* fix unit tests

Closes #2685

* Initial implementation of willAppear and willDisappear

Currently only implemented on pop in StackController

* call clearOptions on super
* TopTabs visible

* fix unit

* generate id only when not already provided

* allows passing id

* fixes #2652