Currently the default NavigationReactNativeHost only adds the NavigationPackage. Users of React Native Navigation may need to override additional methods in ReactNativeHost. This change allows advanced users to provide their own implemenation of ReactNativeHost, with the requirement that they add the NavigationPackage themselves.

Closes #653

Reflecting word that v1.0 doesn't support 0.52+.

* added the ability to change the backing controller's preferredContentSize through props.

* added some documentation outlining preferredContentSize and modalPresentationStyle properties

* overlay support

Only reason to offload icon loading to background thread is to avoid
supposed network on main thread calls which happen only in debug since
icons are passed loaded from localhost.

* Change topBar backgroundColor to Color object

* StackLayout implementation

Unfortunately, this commit also contains a lot of refactoring and a few
bug fixes relating to styles.

* TopBar is not part of Component, instead it's a part of StackLayout
  and shared between all components pushed to the stack Similar to iOS.
* Handle ScrollEvent in ReactView instead of passing the listener down
* Implement Fraction and Text null objects for style params
* Converted a few style params to null objects. This fixes some styles
  being applied even when they were not specified explicitly.
* Stop sending null promise to commands
* Seperate push and pop into animatePush/push and animatePop/pop
  to avoid boolean param

* Adapt TopTabs to new API

This reverts commit abdb6e90a0.

* setTabButton -> has now the property 'label' to change the label of the TabButton

* Add to documentation

* [BugFix] use i instead of 0 to check all TabItems

* setStyle -> to change bottomTabBar

* update android

* remove hass...-functions

* update iOS set TabStyle

* iOS change icon color on buttonTabColor has been changed

* iOS update style-update rutine to update each viewcontroller in a NavigationViewController
tabButtonColor improvement

* iOS add forgotten header declaration

* iOS fix c&p error

* [Android] initialize colors for an empty AppStyles-Object

* [Android] fix update style of tabbar on display screen

* [Android] revert eventbus changes
[Android] apply guyca's solution

* [Android] rn 50 compatibility

* remove comment

* Support launch storyboards as splash screens

* default options support
* refactored navigation options

Application class can now be accessed statically using Context to access AppModule
which provides dependencies needed throughout the app.

Related to #2485 #2302 #1851 #1583

* Deleted getContentView method
* Delete Custom dialog code
* Delete topTab code
* sendOnNavigationButtonPressed was pulled to a dedicated interface

* Ensure ReactView isn't created after it's destroyed

Fixes #2490

* Rebase fixes and renames

https://github.com/wix/react-native-navigation/issues/1397

* readme

* doc

* topbar fix

* rm doc

* options presenter fix

* rm userless stuff

* WIP

* WIP

* WIP

* translation

* WIP

* todo

* draw under

* fix merge

* merge fix

* more merge fix

* improve calc

* animation improvement

* fix tests

* refactor

* refctor

* tests

* fix test

* anim improve

* rm outdated

* refactoring

* more refactoring

* tests

* refactor

* hotfix

* more refactoring

* refactor

* some more refactoring

* refactor

* Collapse topbar