Return Promise rather than Deferred from public methods, but as usual shimmed with the addCallback() and addErrback() methods for backwards compatibility.
Return Promise rather than Deferred from public methods, but as usual shimmed with the addCallback() and addErrback() methods for backwards compatibility.

Refs #16430 !strict.

git-svn-id: 674a2d6b1e32e53f607eb824547723f32280967e@30125 560b804f-0ae3-0310-86f3-f6aa0a117693

redaktor/deliteful