Allow Arbitrary Local Names

[xmppjingle]

Allow Arbitrary Local Names when sending.
To avoid conflict or backward compatibility issues, a tuple format was added to send/ , allowing {Name, Key}.

[uuid0]

I've added a send/4 function to zabbix_sender.
You can now use zabbix_sender:send(Ref, Key, Value, [{local_name, LocalName}]) when using a named server's Ref or a Pid or zabbix_sender:send(singleton, Key, Value, [{local_name, LocalName}]) when using the singleton server.
Does that work for you?
If it does, I'll create a new version tomorrow.

The {LocalName, Key} variant of send/2 and send/3 could be added, but I wanted to keep the interface straight.