lax #5176 make a cleaner custom.py module [resolved]

The custom.py module should only be a skeleton that shows what the developper is able to customize.

The configuration part (i.e. what components are included, what kind of authentication is used, etc.) should go in a separate module, say appconfig.py.

The application schema should be loaded transparently by the main.py module.

custom.py could define a postinit callback that would be called by main.py once everything is loaded.