bash_profile: use auto colors to avoid ESC in redirections

Piping the result of the `ls` command (alias) to a file will contain escape characters because the `--color` setting for `ls` is defaulting to `--color=always` instead of `--color=auto` (auto means, it will only produce color control codes on a real tty)
Merge pull request #118 from ecki/ecki-fixautocolor

bash_profile: use auto colors to avoid ESC in redirections