This PR adds a common configuration section for all modules (see docs). These modules are then loaded at startup by the homeserver. Modules register their hooks and web resources using the new `register_[...]_callbacks` and `register_web_resource` methods of the module API.  | 
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| .. | ||
| __init__.py | ||
| builder.py | ||
| presence_router.py | ||
| snapshot.py | ||
| spamcheck.py | ||
| third_party_rules.py | ||
| utils.py | ||
| validator.py | ||