refs #6301
- In the migration folder, commands.js changed to builder.js to resolve conflict with the 'commands' inside data/utils/clients/.
- a new data/schema/ folder has been added to hold all the code related to the database schema
- data/utils/clients have been moved to data/schema/clients
- data/utils/index.js has become data/schema/commands.js
- data/schema.js has been split, the definition of the DB schema stays put, the additional checks have moved to data/schema/checks.js
- data/validation/index.js has become data/schema/versioning.js
- data/fixtures has moved to data/migration/fixtures
- data/default-settings.json has moved to data/schema/default-settings.json
