IO integration

Unsettled API - The IO interfaces are new and remain subject to change.

The @ref proactor is a portable, proactive, asynchronous API for single- or multithreaded applications. It associates AMQP @ref connection “connections” with network connections (@ref transport “transports”) and allows one or more threads to handle @ref event “events”.

The @ref connection_driver is a low-level SPI to feed byte streams from any source to the protocol engine. You can use it to integrate Proton directly with a foreign event loop or IO library, or to implement your own @ref proactor to transparently replace Proton's IO layer.