Usage:
    navBarCustomView: 'example.CustomTopBar', // registered component name
    navBarComponentAlignment: 'center' // 'center'/'fill'

* Fix title bar not displayed if it was initially hidden

Also cleaned up VisibilityAnimator.

* Move visibility animator into topBar

Also listen to contextualMenuDismissed event in Actions screen

also report type as ScreenChangedEvent instead of navBarButtonPress.
closes #1144

Usage is identical to switchToTab, closes #842

Support status bar color in Modals

fixes #1034

This commit adds support for the following style properties:
titleBarTitleFontFamily - string, font name in assets
titleBarTitleTextCentered - boolean, default is false

FadeIn ContentView and TopBar when pushing shared element screen

If the screen is pushed with `animated: false` then only TopBar is
animated in. This is a compromise until we expose means to control the
transition of each element on the screen.

* Add view manager

* Don’t update screen style on ViewPagerScreenChangedEvent

* change version to legacy

* Fix headers after rebase

* version bump

* Add image to each list item

* Basics structure is done (I think)

toElement also animates into place, even though values are completely wrong.

* Stop relying on refs to resolve fromElements

* Hide only corresponding fromElement

* Animate sharedElements back into place on screen pop

* Update example project with Dota heroes

* Initial curved animation implementation

* Stop resolving sharedElement refs

* Move getLocationOnScreen to ViewUtils

* Parse control points passed from Js

* Scale animation works

Not sure about pivot coordinates yet.

* minor update to SharedElementsTransition screen

* Minor changes to example screens

* Draw shared elements on Screen

Ignore Z order and draw shared elements directly on screen

* stuff

* Start animation after views are drawn

* f

* Animate text color

* Less allocations when animating text color

* Switch from RGB to LAB 😎

* Save and restore SpannedString

* Use correct status bar height in Android M

* Pass show and hide duration from Js

* Fix flicker when show animation starts

* Make shared elements not clickable

motivation: might be related to some native crash

* Use linear interpolation as default interpolation

* Code cleanup

* Clear SharedElements refs when screen is destroyed

* Code cleanup

* Add decelerate interpolator

* No more occasional flicker on animation start (Hopefully 🙏)

* Add FastOutSlowIn interpolator

* Animate only visible shared elements

* Clip bounds animator somewhat works

* Hope fully no more flickery images

* Add interpolator to each animator

* some work on shared element screens

* rebase fix

* fix lint

* Save titleBarHidden in screenParams when toggling TitleBar

* empty commit

* Adds iOS callback for viewWillAppear/didAppear e.t.c.

* Adds in screen events on Android

* Fixed issue with rightButtons getting ignored in preference for empty Screen buttons

* Android screen lifecycle

This commit is contains a few changes and enhancements to the PR made by simon:

* Use getEventEmitter instead of sendNavigatorEvent
* Dispatch willDisappear and didDisappear events when pushing screens
* Dispatch willAppear and didAppear events when popping screen

call setButtons with empty fab object to remove it

* Implement screenBackgroundColor

* Collapse ViewPagerScreen on TopTab select

TopTabParams are a subset of ScreenParams, moved the properties that
are shared by both classes to BaseScreenParams.
This change was needed to report screen changes properly in ViewPagerScreen

This commit removes necessary hacks which were introduced due to
limitations of previous React Native apis.

Mount/unmount logic isn't coupled to view attached/detached
to window callbacks. Instead, `unmountReactApplication` was added.
We can safely call it when a screen is popped and when application is
reloaded in debug.

* Created Snakbar class to encapsulate Snackbar logic.
* Clicking the action now emits event to current screen
* Action color works