Add default query set filtering to public objects.

Also add in signals to search to allow filtering there.
Don’t global filter.
Force pre formatting on error templates
Kill mail chimp in footer
Remove change site language header
Use proper url routing in footer generation
Merge branch 'master' into staging
Bump version for sphinx ext
Catch profile creation errors
Add project details as an include
Link to proper page in mkdocs. Fixes #1002
Modularize, clean up, and test docker build environments

This modularizes the docker build commands into an environment class to track
the state of the version passed in. Eventually, this will allow for reporting
against the version instance on a per-command basis.

This drops `build.json` output to pass in json on stdin/stdout when calling the
docker run management command. Docker configuration of django settings is now
done with a separate settings file, which allows for override by environment
variables via any variable with the prefix `RTD_DOCKER_`. This allows for
configuration of django inside docker without a customized docker build for
every environment.

Some supporting changes include API serializers that return all instance fields
and removing api access to the sphinx context backend.
Update docs
Fix failing test
Lint on docker mgmt command
Alter docker mgmt command for mocking in tests