Add dotfiles-setup and dotfiles-python

The old dotfiles-install task is not dotfiles-setup. It should only be
necessary to call setup once per system.

dotfiles-install now installs the larger/slower packages and
dependencies I need day-to-day but aren't require to have get dotfiles
running correctly.

dotfiles-python will install some useful python versions, and Powerline
which is used in Vim.
Get dotfiles-ruby to install gems
Add support for Go