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
Merge pull request #3309 from jarinudom/superjarin

Simplify superjarin theme and support chruby
Merge pull request #3283 from jaapz/master

Added VIRTUAL_ENV_DISABLE_PROMPT to steeef.zsh-theme
Merge pull request #3265 from thii/fix-yosemite-broken

Fix Yosemite broken zsh
Merge pull request #3092 from MWers/aws-brew-issue

[aws plugin] Changed brew cmd to properly report if awscli is installed via homebrew
Merge pull request #2871 from wrboyce/extract-pigz

use pigz if available in extract plugin
Merge pull request #2448 from gawashburn/master

Fix autojump script to support Nix installations
Do not use GREP_OPTIONS to set grep parameters

From grep version 2.21, using environment variable `GREP_OPTIONS' to
set common parameters to grep calls is deprecated.

As an alternative, we use a custom function to pass in our defined
`GREP_OPTIONS`, while at the same time preserving any aliases that
called grep.

If we choose the alias way as suggested in the grep documentation,
we'll overwrite any already defined grep aliases, or get overwritten
by any subsequently defined user aliases.