Greeting Hello, world!
This class implements a very simple component that responds to all incoming messages
with a predefined greeting and which returns a vCard for itself when one is requested.
You can change the greeting returned using the optional Greeting configuration setting
This example also exposes a node called somebloke that responds to all messages with
authentic British surprise.
This example uses the higher-level API provided by DJabberd::Agent, from which
DJabberd::Component::External serves as an example of
how to handle stanzas at a lower level by overriding the handle_stanza method.