* tabBarItem support

* apply tab items on tabController initialization

* e2e test

* refactored bottomTab item

* tests fix

* tabItem testID fix

* renamed tabBadge to badge

* fix merge

* BottomTab fix

* removed BottomTabs

* Revert "Improve getCurrentlyVisibleScreenId on iOS with drawers. (#2052)"

This reverts commit 2c30a52bb9.

* Revert "introducing navbar shadow on iOS (#2339)"

This reverts commit 8fd496e0c9.

* Revert "This fixes an issue with a custom title-view (which has a title and a subtitle) appearing at the left side of the nav-bar instead of the center during a transition animation: when a screen with this title-view is being pushed or when you pop back to it. (#2384)"

This reverts commit 3f7f6c2612.

* Revert "Now allowing the custom nav bar to take up the whole space on iOS (#2306)"

This reverts commit 74a02ccfc5.

* adds shadow opacity, shadow color, shadow offset, shadow radius to navbar for ios

* mentions ios shadow in styling-the-navigator docs

* Rename TabBar options to BottomTabs

* Restructure docs

* upstream merge

* Fixed bad merge

* More bad merges

* Mostly done, however a few properties missing and tests remain.

* async icons loading

* Left button

* Whoops!

* Added button size

* updated docs

* refactor

* Rebase fixes

* Rebase fixes

* rebase fix

* Rebase fixes

* rebase fixes

* reset contributing

This happens because the title-view is being created again when RVVViewController appears. There's probably no point in setting the title-view again with the same data when it already has it. The title view setup is done anyway in RCCNavigationController.

This can be easily reproduced by calling "this.props.navigator.setSubTitle({subtitle: 'a subtitle'});" from the constructor of a pushed screen.

* minor refactor - moved some logic from view o controller

* readme

* doc

* topbar fix

* rm doc

* options presenter fix

* rm userless stuff

* added backgroundImages options

* update readme

* backgroundImage fix

* added unit test

* async await for push and showModal

* async await for push and showModal

* refactored custom transitions

* refactored custom animations

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

- Also the custom nav bar reacts well to orientation changes
- Fixes: https://github.com/wix/react-native-navigation/issues/1893

* It now works well on iOS 11 as well

* v1.1.314 [ci skip]

* Added optional fixedWidth property to the Android side menu

    - Fixes: https://github.com/wix/react-native-navigation/issues/510

This code block appears fine on GitHub, but is malformatted on the site. This commit updates it to fit the format of other code blocks in the docs, so it should appear okay.

* v1.1.314 [ci skip]

* Added optional fixedWidth property to the Android side menu

- Fixes: https://github.com/wix/react-native-navigation/issues/510

* Added fixedWidth drawer param to te top-level-api doc

* drawUnder for topBar and bottomTabs

* test fix

Resolve promise when startTabBasedApp and startSingleScreenApp complete.

Slightly changes topTabs node declaration and removed the container from it.

* Further work on TopTabs and some refactoring

* OptionsPresenter receives views as params
* Remove TopBar and style logic from ViewControllers, these are the OptionsPresenters concern
* StackAnimator isn't coupled to LinearLayout
* Convert Runnable to lambda
* ContainerLayout now implements ReactContainer interface
* Enable desugaring in playground app

* TopTabs unit tests