Update docker-library images

- `django`: brand new image! \o/
- `docker-dev`: 1.4.1
- `gcc`: 4.8.4
- `mariadb`: 5.5.41
- `mongo`: 3.8.0-rc4
- `node`: 0.10.35 and NPM 2.1.16
- `postgres`: minor formatting/output changes
- `rails`: 4.2.0 (and use Ruby 2.2.0)
- `ruby`: 2.2.0