Some fixes to statcalc

Mainly, switching the order of application of boosts. The old way was causing
a small error in the result.
Add about message
Add about message

To set the about message, make a key in the bot's config named 'aboutmsg' and
set the value to a string that you want to be displayed when someone sends
the bot a PM 'about'.
Set a default value for info[:what]

This stops many triggers from crashing
Forgot a @ before a variable name
Forgot a couple of @'s
Triggers can have elevated priority now

All triggers have priority 0 by default. However, if you set the :priority
property of a trigger (t[:priority] = xxx) you can make it fire before
other triggers that match on the same message.
Better banlist handling (see below)

First, banlists are now either local or central. Central banlist management
has not been implemented yet but even once it is, it can only be used by
one bot. If you're running a bot that's not called 'stretcher', you won't
be able to use this feature. You have to store your banlists locally in the
bot's directory.

Also, there are now banlists for multiple rooms. They are initialized on-
demand.
If banlist already contains user, say so
Revamp the userlist to support multiple rooms

Again, they are created on-demand before any other triggers should execute
Another autoban overhaul

Reason and !ab'er are logged and can be checked by mods

New !ab syntax: !ab <user>, <reason>, where the reason is mandatory
New command: !cb (in PMs, it's <user>, <room> and in a room it's just <user>)
  to check the current ban status of <user>

Banlist checking syntax is still banlist <room> and only in PMs, but I might
merge this into the !cb command.
Fixed a small bug in !ab
Any battle type supported now
Update config-example.yml
Remove extra print statement
Trigger reloading

syntax: !reload <trigger id>

NOTE: your name needs to be in the bot-whatever/ directory's file
'accesslist.txt' for this command to work.
Add 'quiet' option to !ab

If quiet, the bot won't attempt a /roomban etc.

Command: !abq / !uabq
Crash reporting

Also turns off trigger when it crashes
!toggle <trigger> to toggle its on/off
Add has_access