Slate: add layout for "Grotto" monitor, Adium tweaks

Add support for the vertical monitor in the "Grotto" at work.

At the same time, teach all the layouts what to do with Adium chat
windows.

Signed-off-by: Wincent Colaiuta <win@wincent.com>
*sh: add /usr/local/sbin to PATH

Homebrew installs nginx there, so may as well add this to the PATH.

Signed-off-by: Wincent Colaiuta <win@wincent.com>