v0.9.2-beta patch release

Another day, another release. I think this should be pretty stable, but there have been a whole lot of changes underneath the hood (to try and make things cleaner, safer, and more stable). The main visible changes between this and -alpha are the addition of a new way to format MOTDs (add colours, bold, and italics), and that we've removed the REST API!

Config Changes

• motd-formatting key added under server, which supports MOTD formatting characters.
• rest-api section removed from server (since we no longer support the Rest API).
• ws-listen key removed from server (since we no longer support websocket ports).

Added

• We now support the PROXY command (letting people use HAProxy to terminate TLS and similar).
• We now support using escaped formatting codes in the MOTD (tl;dr easy colors, bold and italics).

Changed

• D-LINE and K-LINE code is now cleaner under the hood and less likely to crash.
• Rehashing is now safer.
• Server opers could always speak on channels, even when they shouldn't be able to. Now they aren't above the law.

Removed

• Removed the draft/message-ids cap since... it doesn't actually exist. The feature is now enabled by default when clients request the draft/message-tags-0.2 capability, as written in the Message IDs spec.
• Removed websocket support (conflicted with existing larger IRCd's implementations and not used by any real clients).
• REST API has been removed, until we can build up the web interface in parallel with it.

Fixed

• AWAY was sending an incorrect mode string, and now sends the correct mode string (thanks @jwheare for pointing this out).
• Fixed some bugs with our MONITOR implementation which meant we weren't returning the right info to clients.
• The Moderated (+m) and RegisteredOnly (+R) channel modes could not be set. Now they can be set.