jaredpar/VsVim — pull request #841 by ajtack (2012-03-30 13:27:00+00:00)
Title: Implemented :vsplit (:vsp) using NewVerticalTabGroup

Based on the result of [this StackOverflow question](http://stackoverflow.com/questions/9864233), I used the `NewWindow` and `NewVerticalTabGroup` commands in series to support vertical buffer splits.

I assumed that the :vsp command would accept similar arguments as :sp in the future, so I reused the same parsing path.

I verified this by hand; **is there a place I should be adding a test?**