Go to the most recently visited file when closing a file

[TomMalbran]

This would add what was suggested in #2091

[redmunds]

This works great, but it seems to duplicate the logic that's already in the getNextPrevFile() function. Can you just call that function instead?

[redmunds]

Done with initial review.

[TomMalbran]

Done. Totally missed that function there. Had to move it up to use it just to pass JSLint.

[redmunds]

This works great in this case:

1. Have multiple files open in working set
2. Select and remember a file in working set
3. Single-click to view a file in project tree file that's not in working set
4. Press Cmd/Ctrl-W to close current file

Result: it switches back to file previously being edited in working set

But it's not working in this case:

1. Have multiple files open in working set
2. Select and remember a file in working set
3. Select a different file in working set
4. Close current file

Result: I haven't figured out the pattern, but in most cases it does not re-select the file being edited in step 2.

Note that there are several ways to close a file in Brackets, so be sure to test all of these:

1. File > Close
2. Cmd/Ctrl-W
3. Move mouse over and click on x icon
4. Right-click > Close

[TomMalbran]

Not sure how I missed this. I did tested and worked, maybe the code wasn't fully updated. But this time it does work in all the cases.

[redmunds]

Looks good. Merging.