fix issue on -ne tests

added red prompt when both ahead and behind upstream branch

Update README.md (#2)

Added iterm set font

Removed prompt_context portion of the prompt (not using it, and it may causes some issues on MAC no having cmd)

Fixed some bad explanations on README

Fix comment in install script

Renamed iml file after github repo migration

Fixed 'prompt_git:13: permission denied:' error when working on a detached head

Displaying stash size

introduced displayed_ahead variable

Greatly simplified ahead/behind calculation

renamed theme to agnoster-fcamblor

Provided screenshot for the theme