nested_navigator_tabs 0.2.3

Tabs with nested navigators and multiple backstack handling stategy. Also includes correct visibility detection for the inner pages.

[0.2.3]

• Added onGlobalStackChanged listener to track page and tab changes

[0.2.2]

• Fixed exception when isFirst isn't set

[0.2.1]

• Missing changelog
• Formatting

[0.2.0]

• Backstack handling strategies
• RouteAware events inside the tabs

[0.1.0] - Initial release

• Initial release