Better UI for adding contacts from foreign networks

[Massimiliano Mirra]

It is not reported anywhere that contacts from foreign networks should be added using a special escaped sequence (like foo%<email address hidden>), so users are effectively unable to add contacts from networks they use already.

Add a "network" combo box to the "add contacts" dialog. It should contain items like "MSN", "ICQ" etc. User would input <email address hidden> in the address field and escaping would be handled transparently. If user selects a network the user isn't yet connected to through a transport, he might be given the option to register with the transport.