There's not much sense in saving copies of everything DanbooruBot sends
in DanbooruBot's inbox. They probably won't be checked so it just bloats
the dmails table.
Sends automated dmails from `Danbooru.config.system_user`, rather than
whichever user is performing the action happens to be (usually User.admins.first).
Also adds a notice in the view that the dmail was automated.
/dmails is restricted to viewing dmails for CurrentUser only (due to
Dmail.visible in the index action). Remove owner_id from subnavbar links
in /dmails, and don't support it in /dmails?search[owner_id], since it
doesn't actually do anything.
Also removes related dead methods and fixes tests that didn't test owner_id properly.
* CurrentUser.dmail_count caused an unnecessary COUNT(*).
* CurrentUser.dmails.unread.present? caused *all* unread dmails to be
loaded. We want to only load the first one.
Allows '%' and ',' in tag names. There's no technical need to forbid
these characters.
Fixes an issue with these characters being stripped away inside metatags
(e.g. tagging a post with `pool:ichigo_100%` strips away the '%').
Makes these tag names invalid when tagging posts:
* Blank names (e.g. ___).
* Non-ASCII characters (Japanese text).
* Non-printable characters (e.g. control characters < 0x20).
* Leading or trailing underscores, or consecutive underscores. Reason:
`_foo__bar_` and `foo_bar` both render as `foo bar` in the tag list.
* Leading `-` or `~`, or '*' (-foo, ~foo, foo*bar). Previously
these were silently stripped, but that meant tagging a post with e.g.
`*-foo` tagged the post with the invalid tag `-foo`.
* Tag type prefixes (e.g. `character:character:hatsune_miku` no longer creates
the literal tag `character:hatsune_miku`).
* Metatags (order:score, user:evazion, etc).
