Add db_table and verbose_name for all models.
Review Request #375 - Created Feb. 6, 2017 and updated
In preparation for making use of Django 1.8's AppConfig for all our apps (and in doing so, rename them to be `reviewboard_*` instead of `*`), we need to explicitly define the `db_table` for existing models so as to retain backward compatibility. While I was going through here, I also defined `verbose_name` and `verbose_name_plural` for every model, setting them to be localized strings in title case. We had a mix of things in here, often only defining `verbose_name_plural` when we had something that needed to pluralize with "ies" instead of "s" (and not localized). A recent change added these for the `reviews` models, but these were all in lower case. Testing done: - Ran unit tests. - Started the devserver and looked through the db admin to see the new casing on localized strings. Reviewed at https://reviews.reviewboard.org/r/8704/