* add headerBackTitleStyle screen option
since the title is customizable, the back title should too.
* add documentation for `headerBackTitleStyle`
* make absence of headerBackTitle not affect return value
* merge styles so current scene can override
If there's no last scene, return the `headerBackTitleStyle` from the
current scene.
Otherwise return the `headerTitleStyle` from the last scene, and the
`headerBackTitleStyle` from the current scene, with the latter having
precedence.
* take headerBackTitleStyle from current scene
also the title style of the last scene is no longer taken into account
* Implement getPathAndParamsForState for StackRouter
* Add test to make sure `params` is correct in getPathAndParamsForState of StackRouter
* chore: fix flow
* Fix Modal Gestures
* Update StackNavigator.md for gesturesEnabled to include modals again
* Remove modal gesture todo
* Gesture response distance top, side => vertical, horizontal
* [ReduxExample] Programmatically generate initial state
* [ReduxExample] Return original state if nextState is null
* [Docs] Add getStateForAction to redux integration example
* [Docs] Add link to ReduxExample app
* [Docs] Give each example a 'DRY' README linking to real docs
* [Docs] Clean up the Contributors guide a bit
* [Docs] Remove numbers from sections in Contributors guide
They don't seem very meaningful, and don't need to be done in order
* Force the back button to be recognized as such by screen readers.
* Update HeaderBackButton.js
* Update HeaderBackButton.js
* Update HeaderBackButton.js
* Format remaining issues
* [Example] Get tests passing on ReduxExample and NavigationPlayground
* [CI] Use more vague versioning so we're always up to date
* [CI] Test that the example apps run without error
* [CI] Install the current local version of react-nav before testing
* Fix tabs => spaces in ReduxExample/package.json
* Remove LinkingExample entirely
It's now part of NavigationPlayground.
* [Example] Upgrade dependencies to fix the ReduxExample app
* [Example] Also upgrade and fix the LinkingExample app
* [Example] Update MainApplication.java to fix Android API
Centered titles are generally specific to iOS, left alignment of the title appears more common in platforms outside Android and iOS.
This also fits better with the rest of the conditionals that test for iOS instead of Android.
`screenProps` were not being passed to `CardStack` and consequently not
available for the navigationOptions function in components using
`StackNavigator`.
