Update PopUpManager.as

hi, I found "root setter" function has a issue.
...
var popUp:DisplayObject = popUps[i];
var overlay:DisplayObject = DisplayObject(POPUP_TO_OVERLAY[i]);
...

the overlay always return null, I think because 'POPUP_TO_OVERLAY[i]' should be 'POPUP_TO_OVERLAY[popUp]';
AIR 3.8 support
updated release notes for 1.1.1
updated release notes for 1.1.1
updated release notes for 1.1.1
Targets SWF version 18 (FP 11.5 and AIR 3.5) in builds to support BB10
Text Editors: visibility fixes when text is empty (closes #693)
GroupedList: fixed null reference on item renderer maps when changing item renderers (closes #688)
Item renderers: accessory is cleared if itemHasAccessory is set to false (closes #689)
Merge pull request #692 from lynxerzhang/patch-1

Fixed issue where changing PopUpManager root failed to transfer overlays.
Merge branch 'master' of github.com:joshtynjala/feathers
Merge branch 'master' of https://github.com/joshtynjala/feathers