Do not define $GEM_HOME

Defining it breaks gems for all users who neither use RVM nor rbenv,
but have a different default Ruby version nonetheless.

Signed-off-by: Sorin Ionescu <sorin.ionescu@gmail.com>
Use correct option for pacman search aliases
Stop module loading when external code fails to source
Comment an unnecessary style
Merge remote-tracking branch 'upstream/master'
modules/prompt/functions/prompt_gentoo_setup: sync with gentoo

see https://bugs.gentoo.org/show_bug.cgi?id=453584
modules/utility/init.zsh: add option to rip-cd alias

-U, --unknown         whether to continue ripping if the CD is unknown
[Fix #477] Add instructions for updating Prezto
[Fix #479] Start only one ssh-agent instance
Merge remote-tracking branch 'upstream/master'

Conflicts:
	README.md
modules/utility/init.zsh: add VDPAU_NVIDIA_NO_OVERLAY=1 to mplayer-vdpau alias

see http://www.nvnews.net/vbulletin/showthread.php?t=156621