Comment 2 for bug 771751

I didn't mention the bug number in the message because there are many
ways of getting a notification about a bug besides being subscribed to
the bug itself.

In the linked branch I changed the message to "Edit bug mail". The same
message is used to lead the user to the equivalent page on a bug target,
so it seemed like a good choice.

I would like us to standardize our terminology some though. We make
references to "bug mail", "subscriptions", and "notifications" in
various places. I doubt users are interested in any of the subtleties
these phrases convey. If any persons endued with the powers of UI
design agree, please create a bug.