[emacs] Change some comments to make automatic indention happy

`emacs-lisp-mode' will indent comments starting with a single
semicolon to `comment-column'.  For comments indented according
to the code, two semicolons need to be used.
[emacs] Use `setq-local' and postpone loading of `google-c-style'

Instead of explictly calling `make-local-variable' use `setq-local'
macro which is shorter and postpone loading of `google-c-style' to
the moment it is really needed.
[emacs] Prefer block comments even in C++.
[irssi] format notices the same way messages are formatted

irssi (and basically all IRC clients) have very verbose and weird
formatting of NOTICEs.  There is no apparent reason for that
though, plus it makes output from bots that use NOTICEs rather
ugly. Format notices similarly to the way messages are formatted
except that “>” is replaced with “]” – a very non-intrusive
difference that indicates if something was a notice.
[sawfish] clear SAWFISH_QUIT_CMD_FILE environment variable

The SAWFISH_QUIT_CMD_FILE pollutes environment variables spawned by
Sawfish, so unset it so that no child processes receive it.
[shell] add , function which prints arguments separated by comma
[emacs] Update `set-key' documentation
[emacs] Update M-SPC binding
[emacs] Always disable vc mode
[sawfish] (getenv "HOME") only once and add binding for getotp.sh --last
[shell] Make sure completion is disabled and fail on globs
[xinitrc] Add redshift invocation (if configuration file found)