The 'admin' module will be split off from 'framework',
where 'framework' only provides (mostly) frontend-agnostic PHP classes.
For example, HTMLEditorField.php has a TinyMCEConfig.php driver,
but doesn't come with its own JS includes.
Core.php can rely on composer’s autoloader now that classes are PSR-4
compliant.
If you stuck to the core modules, you could even remove ClassLoader’s
autoloader, but this would break any module that hasn’t been updated
to support PSR-4, so I’ve left it in.
In the future, it would be good to apply SilverStripe’s auto-loader
only to those modules that aren’t coded to use PSR-4, as it would
make class loading more predictable.
