Having the ls alias default to `ls --color=auto` caused it to break on
OSX, since the version of ls that ships with OSX doesn't support the
`--color` option.
This change moves the alias into lscolors, since we already have a check
for OSX vs non-OSX (in my case, Linux). This allows the alias to work as
expected on Linux, while the environment variable LSCOLORS provides the
coloring option on OSX.
Prior to this change, I was using Bash as the default shell, but I have
now started using Zsh, which has more features.
This change adds the zshrc and related plugin files to source control
and installs them along with the bashrc files. This also updates tmux to
use zsh as the default shell and command.
nirenjan