Reordered configuration to separate linux states from the base configuration. Added several new OSX-specific states.
Updated and added support for various OSX packages.

Updated:
- 1password
- alfred
- caffeine
- ccmenu
- dropbox
- dmg_and_install script to install only packages that haven't been
  installed

Added:
- firefox
- iterm
- system_preferences.remote_desktop
- xquartz
- shiftit
Simplified install scripts. Aded MacVim install.