Config.{set,get,default} should only be called on settable config
variables. Detect whether the given argument is settable and emit an
error if not. This avoids an uncaught exception.
Tons of changes. Here's the summary of things that matter most:
* There is no more supybot.fix.
* There is no more supybot.webutils; now there is supybot.utils.web.
* It's no longer webutils.WebError, but just utils.web.Error.
* You shouldn't import itertools, ideally, but instead import utils.iter.
* No more using imap/ifilter in commands unless absolutely necessary. It's
premature optimization and annoying.
* utils.str.format isn't quite ready yet, but will be soon. That'll be the
next big thing to fix in our code.
