LayoutGroup: new component (closes #542), LayoutGroupListItemRenderer: new base component for custom item renderers, ScrollContainer: minor tweaks to docs and code to match LayoutGroup.
Button: support long press (closes #192)
Documentation: added some default values to properties (references #569), improved some API descriptions
Scale9Image, Scale3Image: distort when smaller than min width and height (closes #457)
ValidationQueue doesn't use Starling in constructor anymore
Merge pull request #587 from nka1024/master

ValidationQueue doesn't use Starling in constructor anymore
Merge branch 'master' of github.com:joshtynjala/feathers