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
Respect original PATH definitions on install

The exporting of PATH as a fixed string would clobber any system-wide
paths added to env after installation. Instead, we now read any existing
PATH exports from previous config files and copy those from the user's
bash config, or else default to a basic prepend-only example that
respects the system environment.
Use sed instead

This needs the extra newline character defined in a variable because
shells treat the ${} expansion differently for replacing newline characters.
Change history alias into a function

This commit changes the history alias into a function which puts
the passed arguments before `-l 1`. It also provides a temporary
workaround to the lack of a `history -c` command in zsh.
This resolves #739 and resolves #789.