Fix behaviour of 'Y' in Vim.
Add my Git bpush and bpull commands.

These provide the interface that I've always wanted from push and
pull.
Move from oh-my-zsh to a hand built ZSH configuration.

I go tired of not knowing whether a particular behaviour came from
ZSH, oh-my-zsh or my own configurations. Performance wasn't great
either. I wasn't using that many oh-my-zsh plugins anyway, so I
decided it'd be better to just do things manually.