Add Ctrl-Tab/Ctrl-Shift-Tab to menus

[njx]

We have awesome functionality (courtesy of @peterflynn) to make Ctrl-Tab/Ctrl-Shift-Tab switch between open documents, but it's not in the menus, so a lot of people don't know it's there. Many apps don't have these in the menus, so we originally didn't put them in to avoid clutter, but I think it can't hurt to advertise the functionality right now since our menus aren't that long anyway :)

[pthiess]

Reviewed - assigned to Raymond

[RaymondLim]

The above comment does not apply to this. It was a typo and meant to address #1440.

[twoquestions]

If you're looking to fix this in Sprint 14, I've added a pull request that adds these two items to the menu.

[RaymondLim]

FBNC to @njx

[njx]

Confirmed. Nice!