Added new vimcmd keybinding and reverted EDITOR and VISUAl variables.
Added new vimcmd keybinding and reverted EDITOR and VISUAl variables.

I want to make use of the push-line feature in ZLE, so I've mapped it to
'z' in vimcmd mode, since it was currently unused. I've also reverted
the EDITOR and VISUAL variables to their previous values, since you
can't pass flags in them.

melloc/dotfiles