upgrade message-tags to non-draft version

fix #300

remove indirections in Fakelag and NickTimer

Also upgrade RENAME to latest draft specification

work around a Tor bug

https://bugs.torproject.org/29665 describes how single-onion circuits
will close unless the client sends data every 60 seconds. To cause the
client to send these messages, have Oragono send the client a PING every
30 seconds.

add Tor support (plus a few random changes)

fix bashisms in install.sh

Use /bin/sh rather than /bin/bash

This makes it much easier to run on alpine which ships with
only a /bin/sh by default.

upgrade golang to 1.12, fixes #406

deprecate plaintext on 6667

fix #409

fix #384

New Crowdin translations

Independently of this, ClientLookupSet.Resume ensures that at most one
resume can succeed, so this doesn't actually change the behavior.
But ResumeManager should be a standalone example of how to implement
resume without race conditions.