This commit makes the following change to the Edit Bookmark
modal window for clarity:
* If the user is editing an existing bookmark without a reminder set,
hide the "none needed" option. This will draw more attention to the
delete button.
* If the user is editing an existing bookmark with a reminder set for the
future, change the "none needed" option to say "remove reminder, keep bookmark"
To do this, I needed to provide an option to override the labels
for time shortcuts in certain cases, so I could keep the NONE shortcut
but have the different wording.