commands: #nil? instead of == nil
preload: write pid file on -f
doc: update github url again (sorry)
scripts/imgur: update to api v. 3, get more data

Side effect of this change: we need to use a client ID to authenticate
API requests. I have gone ahead and included one I generated, since we
aren't actually doing oauth. If rate limiting becomes a problem, I will
either remove the ID or request whitelisting.
scripts/seen: changed channel detection method to be compliant with the server's 005
modules/url_handler: add delete function
scripts/4chan: remove completed todo
lib: module_loaded? in preparation for url shortener module
scripts/backspace: new backspace script (for ^H and such)
scripts/backspace: remove erroneous buffer module requirement
scripts/backspace: formatting update for readability
ircconnection: add is_channel_name? function
message: use IRCConnection#is_channel_name?
channels: change topic to attr_accessor, fix topic events
add helper method "channel" to quickly access current channel object
core: add :periodic event which fires every 30 seconds
scripts/reminders: new reminders scripts
core: fix typo on 3f7a3d09466241cb72b9948cd2e9152704be9e99
scripts/reminders: remove some debug logging
scripts/channels: use periodic event rather than PING for channel maintenance