Review Board 3.0 introduces support for only notifying the owner of a

review request via e-mail whne publishing reviews. This was the

"... to Submitter Only" option in the Publish Review button, and it had

a corresponding to_submitter_only flag provided in the API, signals,

and other methods.
In an effort to begin standardizing on "owner" as the terminology

instead of "submitter," this change renames all the options and UI for

this feature. This feature wasn't shipped prior to 3.0, so it's safe to

ignore backwards-compatibility here.
It also improves the "to Submitter Only" labels by better describing the

default behavior. The new labels are "... and only e-mail the owner".

The documentation has been updated accordingly, and now mentions that

other extensions/integrations may also decide to react to this option.

All Python and JavaScript unit tests pass.