skip linking LICENSE file during install
Use rcm instead of ./install.sh

The rcm suite is designed to replace the `./install.sh` script found in
this and many other dotfiles repos across GitHub. By using rcm users can
combine multiple dotfiles repos, tag dotfiles, have host-specific
dotfiles, and other powerful features.

This commit removes `install.sh`, updates the README, adds a post-up
hook that vundles the vim bundles, and adds a `rcrc` configuration that
ignores `README.md` and `LICENSE` and sets the dotfiles directory to
just `dotfiles`.
Always update from vundle

Previously, the after-up hook would only do a `:BundleInstall` when
installing vundle for the first time. This is inconsistent with the
pre-rcm process, and also less convenient.
Cleanup zshrc

* remove duplicates with zlogin
* order by functions first, then bindings, then exports
* lowercase `setopt` arguments for consistency with `setopt` output
Change dotfiles directory for rcm