Fix an issue where the New Relic agent always started in the production
environment, even when a license key wasn't configured.
Also make the New Relic agent log to stdout instead of log/newrelic_agent.log.
Set sensible defaults for connecting to the database. By default, we try
to connect to the `danbooru2` database running on localhost as the
`danbooru` user. These are the defaults recommended by the install
guide.
If you need to change the database settings, set DATABASE_URL in
.env.local or on the command line:
# .env.local
DATABASE_URL=postgresql://danbooru:password@localhost/danbooru2
# command line
$ DATABASE_URL=postgresql://danbooru:password@localhost/danbooru2 bin/rails server
This eliminates the need to copy script/install/database.yml.templ to
config/database.yml during installation and during deployment. This is
so that Danbooru works out of the box without extra configuration. In
particular, this is so that we can run Danbooru in a Docker container
without having to set DATABASE_URL.
Drop support for https://danbooru.donmai.us/cache/tags.json. This was a
nightly dump of the tags table that was originally added in #1012. It
was never documented and never really used except for by the DanbooruUp
extension.
