Animate linear translation also when animating shared element bounds

Separated iOS and Android only properties.

Apply easing on shared element bounds transformation

Animate image scale and bounds

This commit properly animates images with different aspect ratios.
By default, regular scale animator is used which scales up or down the entire ImageView.
If `animateClipBounds={true}` is specified on the **to** `SharedElementTransition`, instead of scaling the View, the actual Drawable bounds and scale is animated which prevents the image from appearing distorted during the transition.

* Add ability to set attributes of navigation bar buttons separately.

* Added ability to set button style when calling `setButtons` method.

* Add documentation.

fixes #942

* Send willAppear didAppear for initial screen

* empty commit

- compileSdkVersion 25
- buildToolsVersion "25.0.1"

Support status bar color in Modals

fixes #1034

* Support custom font in the Menu items.

* Fix check for custom font.

Add tabBarTranslucent style option in tabsStyle