[server][AMQPConnectionInfo] Make AMQP related connection info as object

There are many items for connecting a AMQP broker. With this change, it
is easy to handle these items.
[server][HAPI JSON] Use AMQPConnectionInfo
[server][AMQPConsumer] Add "connection" prefix to "info"

Because "info" is too short name for the context.
[server][AMQPConnectionInfo] Use StringUtils::hasPrefix

We should use existing feature if the feature is exactly same. We should
not create the same feature multiple times.
Merge pull request #438 from project-hatohol/introduce-amqp-connection-info

[server][HAPI JSON] Introduce AMQPConnectionInfo