Regen amqp_framing.[ch] to include autogend docs.

Doing this because the next change will cause a ton of diffs otherwise.
Enable auto_delete & internal for exchange.declare

Enable auto_delete and internal parameters of amqp_exchange_declare() in
codegen. These were once not generated because RabbitMQ did not support these
parameters. The broker now supports these and so should we.

This fixes #218