Channel names in blacklist/whitelist/etc. should be case-insensitive

[inhahe]

I had to figure out why my blacklist wasn't working in #toronto, turned out it was because I set supybot.plugins.SpiffyTitles.channelBlackList to #Toronto (because that's how the network lists the channel, with an uppercase T), but when I told the bot to join I told it to join #toronto, all lowercase. IRC treats channel names case-insensitively (probably according to IRC's special rules for comparing cases where symbols count too), so I think SpiffyTitles should too.