Layouts: added missing inherited event docs for layouts
build script tweak
LayoutExplorer: tweaks to layout default settings
Layouts: added manageVisibility property (closes #302)
ScrollContainer: view port updates layout when scrolling (to support visibility changes on scroll, among other possibilities)
Scroller: removes native stage events on dispose (closes #458)
Header: responds to resizing leftItems or rightItems (closes #456)
Header: responds to resizing leftItems or rightItems (minor tweak)
Item renderers: handles accessory resizing (closes #385)
duplicate variable
Fixed issue with Horizontal- and VerticalLayout and passing "null" as bounds parameter
Merge pull request #461 from bummzack/master

Fixed an issue with the Vertical- and HorizontalLayout
TiledRowsLayout, TiledColumnsLayout: handling viewPortBoundsbeing null
HorizontalLayout: renamed suggestedBounds to viewPortBounds for consistency with other layouts
ScreenNavigator: fix for case when showScreen() is called when new screen is added to stage, but before transition.
Scroller: removed 'view port wrapper' since it is no longer necessary
Panel: added optional footer. link to wiki.
docs tweaks
PanelScreen: clipping is turned off by default
Item Renderers: fixed icon and accessory positioning with inifinite gap (closes #460)