Bug 994865 - [SMS] Make appendThread return whether or not it created a new container, and only sticky.refresh if it did. r=julienw
Merge pull request #18191 from DouglasSherk/994865-sms-stickyheader

Bug 994865 - [SMS] Move sticky refresh call from updateThread to appendThread if creating a new container. r=julienw
Bug 1007569: Fixed screen hang issue. Fixed UI to match UX spec.