added prezto as a submodule
removed oh-my-zsh submodule
switch .zshrc to prezto
zsh symlinks required for prezto
install.sh: never symlink markdown files
prezto is a pain in the arse to configure
zsh_aliases: showopts for zsh
zsh: remove stuff that prezto does; setup some zsh options
install.sh: no .zlogout symlink
zsh: export VISUAL=vim