The main application class has been moved from __init__ to the app
module.
__init__ will contain instead the relevant global variables and the
modules and objects exposed to external integrations - such as
`get_plugin` and `get_backend`, or the `main` itself.
This will make future integrations much easier - the global __init__
doesn't contain any business logic now, it can import anything without
fearing circular dependencies, and it can limit its exposed objects to
those that we want to expose to 3rd-party integrations and scripts.
It will also make it easier to extend the main entry point with
additional logic - such as a supervisor or an embedded Redis server.
The `disable_logging` attribute was only available on events and
responses, and it could only either entirely disable or enable logging
for all the events of a certain type.
The new flag allows more customization by setting the default logging
level used for any message of a certain type (or `None` to disable
logging). This makes it possible to e.g. set some verbose events to
debug level, and the user can see them if they configure the application
in debug mode.
It also delegates the logging logic to the message itself, instead of
having different parts of the application handling their own logic.
The `disable_logging` attribute was only available on events and
responses, and it could only either entirely disable or enable logging
for all the events of a certain type.
The new flag allows more customization by setting the default logging
level used for any message of a certain type (or `None` to disable
logging). This makes it possible to e.g. set some verbose events to
debug level, and the user can see them if they configure the application
in debug mode.
It also delegates the logging logic to the message itself, instead of
having different parts of the application handling their own logic.
Fabio Manganiello