split out zsh configs into shareable units
fix ls alias, fix commented out bindkey
iTerm: focus follows mouse
split vim configs into component modules:

* vim plugins are now managed in ~/.vim/plugins.vim
* spelling tweaks in .vim/bad-speller.vim
* keyboard macros in .vim/keys.vim
* indenting and tabs in .vim/spacing.vim
* cool custom functions in .vim/super-powers.vim
* visual settings + colors in .vim/visual.vim
docs
document zsh options in readme + in config