* Add errcheck linter

* Add config for 'fast' linters

* Fix errcheck lint stuff

* Fix errcheck lint

* Add prefixes to namespace the SQL tables.

This means that multiple components can share a single database schema
without colliding with each other.

Once this lands it will be possible to run a single monolithic dendrite
against a single postgresql schema.

Hopefully this will make trivial deployments and development easier.

* Comment

* Add a database for storing the server keys

* Tweak wording, and comment on the resolution of the timestamp

* Update gomatrixserverlib