wip/swift 4.0beta2 NetBSD

Swift is trying to plug a hole in the XMPP client landscape, and has these aims:

\* Wide platform availability.
\* Doing the "Right Thing" for the user, without configuration.
\* Doing the "Right Thing" with standards-compliance.
\* Targeting the end-users, not the system administrators.
\* Being an XMPP client - not multi-protocol.
\* Concentrating on the most frequently performed tasks.
\* Never interrupt the user with something that doesn't need attention.

Features of interest

\* Easy status setting.
\* Easy room joining and bookmarking.
\* XEP-0258 Labelling for secure environments.
\* Stream compression for bandwidth-saving.
\* Support for the new SCRAM authentication mechanism.