If you attempt to use something other than a string, it will throw an error in some situations. #1318 provides more details about the error. If it is expecting a certain type, the docs should clarify that.
* 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
* 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
* Initial commit
* Remove HybridExample (#985)
* Remove HybridExample
* Remove last mention of HelloHybrid
* Remove console log
* Fix flow and example
* Fix routers api docs
* Keep options in single place
* chore
* Fix styling
* Organise miscs
* Better flow type for screen options
* Flow test website and add more types to options
* navigationOptions instead of prevOptions makes more sense
* Fixes
* Fix up docs
* Fix
* Update route decl
* Provide error when removed API is used
* Remove lock
* Add validators
* Make StacksOverTabs config valid again
* Do not return
* Fix redbox
* Added option to overwrite label style for only if label is as string defined in navigationOptions in DrawerNavigation.
* update doc for labelStyle prop
* change title to label
The example provides styling for the tab icon via the `icon` property in the styles object. However in the example, it is used as `tabIcon` which does not exist.
