Use color grep and ls

Automatically append the color option with the following aliases:

alias grep='grep --color=auto'
alias fgrep='fgrep --color=auto'
alias egrep='egrep --color=auto'
alias ls='ls --color=auto'

For Mac OSX (BSD) ls, something like:

alias ls='ls -G'
export LSCOLORS=GxFxCxDxBxegedabagaced