when prompting to save-as an untitled document, activate that document in the editor
Unit test for Save As bug related to untitled documents (see note at
https://github.com/adobe/brackets/issues/4468#issuecomment-21284958). Fixed
as a side effect of PR #4514.
Merge pull request #4514 from adobe/bchin/issue-4489

Fixed issue #4489- "Save/Close All with multiple untitled documents gives ambiguous Save dialogs"