Changed brew cmd to properly report if awscli is installed via homebrew
Added VIRTUAL_ENV_DISABLE_PROMPT to steeef.zsh-theme

This stops the virtual env name from being printed before it is actually being
used in the zsh prompt.
Merge simplified superjarin theme
Fix autojump script to support Nix installations
Fix Yosemite broken zsh where $PATH var does not get appended correctly.

Sourcing oh-my-zsh immediately after export PATH.
use pigz if available in extract plugin