Adding a listener to "names" and improve documentation
Being able to get the list of connected user when join the channel can be interesting, that why I added the listener.
I improved the documentation by adding all the possible status and their description.
Merge pull request #225 from Belphemur/node-irc

Adding a listener to "names" and improve documentation of IRC Node
REST API for Credentials
Adding RED.nodes.registerCredentials to register the credentials definition server sided.
Adding the property credentials in the template definition client-side.

Connecting the editor to the credential API.
I added a TODO for the validation of Credentials field.
As the other field, the developer should be able to set the credentials as required and also give a validation function.