Fixes #1938 Closes #1900

This commit fixes two issues found in #1838. Fixes #1924
1. Keeps calling the deprecated reactInstanceManager methods when host is cleared
    to not introduce undesired behavior when clearHostOnActivityDestroy return true.
2. call onHostDestroy and onHostPause only if react context exists or is being created.

* remove unused code from tabStyle

* improve dummy screen ui

* set list screen translucent navigation bar

* make RCCToolBarView to composite the UIRootView inside

* add list screen for debug behaviours

* add dummy screen

* ui changes in ListScreen

* add push list screen function without add it to the button to the screen

* add and comment push list screen row

This only happens when you are using react-native@0.48.3, and your XCode is in version 9.0

* Update the comment for tabsStyle in Android

* for -> on

* Update top-level-api.md

Fixes #1844

This commit adds support for fade and slide-horizontal animations for modals and a few other animation related changes:

* Support defining animationType when calling dismissModal
* Support fade and slide horizontal animations for modals
* Slightly reworked current screen animations timings
* Fixed slide-horizontal x offset and removed alpha

This is a breaking change and has to be opt-in. To prevent host.clear from being called,
Override `clearHostOnActivityDestroy` in MainApplication and return false:

```java
    @Override
    public boolean clearHostOnActivityDestroy() {
        return false;
    }
```

If host isn't cleared, the next time the app is opened react context might still be initialized.
In this case we emit appLaunched event which has to be handled in Js:

```js
  Promise.resolve(Navigation.isAppLaunched())
      .then((appLaunched) => {
        if (appLaunched) {
          startApp();
        }
        new NativeEventsReceiver().appLaunched(() => {
          startApp();
        });
      })
```

This converts from using a deprecated attribute.

* add disabledButtonColor in order to set navigation button disabled color

* add disabledButtonColor to the docs

Fixes #1007

* Add font family support on bottom tabs

* import missing classes

* import missing class

* update document

* Support customize icon for left nav button in android

* Add navBar navBarTextFontSize support for android

* Add missing parameter instruction for in app notification

* Merge changes as origin master

Ability to set a flat border under the TopBar. `topBarElevationShadowEnabled` should be set to true if using this feature.

* testing

* test

* try fix props on topTabs

* Test xml menu

* Add titleBarHeight

* Remove test

* Add to StyleParams

* Add topTabsHeight

* Fix styleParams type

* Add navBarFontBold

* Add typeface package

* Remove unused debugging

* add adjust soft input optional config for Lightbox on android platform

* Add doc about adjustSoftInput for showLightBox

* Add initialTabIndex support to RCCTabBarController

* Add initialTabIndex support to BottomTabsLayout

closes #1694

fixes #1675