IRCv3 no more.

I'm tired of childish behavior of nenolod and of his threats.

If someone wishes to continue collaborating without nenolod, welcome to
irc.freenode.net #ircv4
Merge.
Merge pull request #69 from DarthGandalf/ircv3

IRCv3 no more.
Add working group charter and policy.
IRCv3 is not incubated by Atheme anymore.

nenolod agreed to decrease his influence (hence the move of github repo),
and not to abuse his powers (see charter)
Merge pull request #70 from DarthGandalf/ircv3

IRCv3 is not incubated by Atheme.org any more.
specification/message-tags-3.2: clarify that message tags are unordered
specification/capability-negotiation-3.2: fix typo
extensions/multi-prefix-3.1: add an example
Enable cap-notify for CAP LS 3.2