Change bottom tab bar button image at runtime

Add setSubTitle implementation for iOS + docs

Fix dead link

Create BitmapDrawable using a constructor that actually uses the Resources reference

Some navBar button properties were marked as common by mistake.

fixes #1162

Fix missing import of PropTypes throwing an error on iOS

Docs weren't very clear on how exactly to return additional packages, i.e., as a <ReactPackages> list [Line 65]. 
Also changed MyApplication to MainApplication on line 54 (if that is a default and hasn't been changed by the developer).

Render children and pass props to children
Export SharedElementTransition on iOS
Omit children from passed props

Pass iconInsets for tab icon [iOS]

* Update app title (android)

* Add v2 docs placeholder path

Add payload param to handleDeepLink

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

Custom title view in navigation bar support in `navBarComponentAlignment:'fill' | 'center`

Usage is identical to switchToTab, closes #842

Corrected typo in the side menu

* React Native v0.40.0 fixes

* Implement disableIconTint property on Android TitleBarButtons

* Show contextual menu only on Modal, if showing

* Fix crash if font not set in title bar button parameters

This is mostly a workaround to overcome faults in the simple event bus implementation,
also fixes crash when reloading while modal is displayed.

Animate linear translation also when animating shared element bounds

Separated iOS and Android only properties.