Re-add missing opera fix
Fix overlay Reference. Fixes #574
Merge branch 'master' of github.com:Craga89/qTip2
Add common cloneEvent method to reduce code. Fix destroy issues.
Fix an issue where tip was not drawn smoothly on Retina display
This fix resolved an issue in Chrome, where the tip is drawn pixelated on Retina displays, like the MacBook Pro Retina.
Merge pull request #581 from egeriis/retina-fix

Fix an issue where tip was not drawn smoothly on Retina display