Use pre-set $apt_pref variable in Debian plugin
Add super clean, elegant theme (feross)

SCREENSHOTS:

Dark terminal theme: http://imgur.com/wzZO6,rxHHO#0
Light terminal theme: http://imgur.com/wzZO6,rxHHO#1
Use pre-set $apt_pref variable in Debian plugin
Fix sudo check in case it is aliased
Merge branch 'master' of git://github.com/robbyrussell/oh-my-zsh
Merge branch 'master' of github.com:jcassee/oh-my-zsh
Merge branch 'master' of git://www.github.com/feross/oh-my-zsh
Merge branch 'master' of git://www.github.com/jcassee/oh-my-zsh

Conflicts:
	plugins/debian/debian.plugin.zsh