Adding mod_amqp as an event_handler module

Adding mod_amqp as an event_handler module

AMQP(Advanced Message Queueing Protocol) is an event bus protocol
with more info here http://www.amqp.org/about/what

mod_amqp implements the client side of the amqp protocol. Currently
the module supports two separate, but not mutually exclusive usages:

1. Sending a filtered whitelist of events to an AMQP server. The
before the events are sent an amqp routing header is generated so that
downstream subscriptions can subscribe using filters. If the
connection to the remote server is interrupted, the module will
attempt to reconnect.

2. Subscribing to a 'control' channel on the remote AMQP server. When
events are received on this channel if they match a configured filter,
the commands are run locally as api commands. If the filter for the
events being sent to the remote AMQP server include SWITCH_EVENT_API
then the results of the api commands will be sent back to the AMQP
server.

FS-7060 #resolve
Thanks-to: Daniel Bryars <danb@aeriandi.com> and Tim Brown <tim.brown@aeriandi.com>