(rcirc-startup-channels-alist): Add irc.freenode.net and #emacs as defaults.

(rcirc-startup-channels-alist): Add irc.freenode.net and #emacs as defaults.
(rcirc-ignore-all-activity-flag): Remove variable.
(rcirc-authinfo): New variable.
(rcirc-authinfo-filename): Remove variable.
(rcirc-always-use-server-buffer-flag): New flag.
(rcirc): M-x rcirc will automatically connect without prompting.
C-u M-x rcirc will prompt.  Use rcirc-connect to create a
connection in lisp.
(rcirc-process-server-response-1): Remove everything but the nick
portion of the sender so it doesn't need to be done everywhere
else.  Update related code.
(global-map): Remove global keybindings.
(rcirc-get-buffer-create): Make sure rcirc-topic is set.
(rcirc-send-input): Split into several functions.
(rcirc-process-input-line, rcirc-process-message, rcirc-process-command):
New functions.
(rcirc-target-buffer): Add function to determine where to route messages.
(rcirc-user-nick): Save match data.
(rcirc-toggle-ignore-buffer-activity)
(rcirc-update-activity-string): Remove global ignore
functionality, which can be done now by toggling rcirc-track-minor-mode.
(rcirc-track-minor-mode-map): New keymap.
(rcirc-track-minor-mode): New minor-mode.
(ignore): Make the ignore output nicer.  Always print it when adding or
removing nicks.
(rcirc-url-regexp): Improve.
(rcirc-mangle-text): Remove properties before using text in the modeline.
(rcirc-authenticate): Authentication data comes from rcirc-authinfo, not
the file pointed to by rcirc-authinfo-file.
(rcirc-server-prefix): Inherit from rcirc-server.