fix issue with close-save of new document outside of project

Ian found an issue with PR #4437 (which addressed Issue #4238) in which close-saving a new, untitled document, outside of the current project, would result in unusable, leftover items in the working set.

Steps to reproduce the new issue:
1. launch Brackets
2. File > New
3. in the resulting new, untitled-1.js document, type some text in the editor
4. File > Close.  Click the resulting Save button.
5. in the resulting Save As dialog, type a new filename, like 'abcde.js', and select a folder outside of the current project root.  Click Save.

Actual Result: in addition to 'abcde.js', you'd still see Untitled-1.js in the working set list.
Desired Result: that only 'abcde.js' would be in the working set, not 'Untitled-1.js'

This branch change fixes the problem, which resulted from the fact that files saved outside of the current project go thru a different code path when opening the file.  In particular, the now-saved file would be opened and added to the working set by the alternate code path, which wasn't forcing the working set list to be rebuilt when it was done.  So, the fix was to move the call to refresh the working set list to the end of the save-as code, which would be called regardless of which code path was taken.