zsh, shell: rename z-recent alias to cd-last

Signed-off-by: Christopher Larson <kergoth@gmail.com>
zsh, shell: pass SHELL to hub alias -s

Signed-off-by: Christopher Larson <kergoth@gmail.com>
zsh: fix unset of fasd_cache

Signed-off-by: Christopher Larson <kergoth@gmail.com>