ref: b2f3a9a952493ffcf467eafa59803c27fa099e2d xmpp/ping d---------
all: bump to new xmlstream and fix flushing
all: improve documentation
xmpp: use new JID API
all: update copyright message

[ci skip]
all: fix tests
all: update WrapIQ to support all IQ attrs

This also fixes bind
all: rewrap copyright comments/use xml.TokenReader
ping: rename PingIQ to IQ
ping: implement XEP-0199: XMPP Ping