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 'sorin/master'