title: MacVim: how do I set a left gutter (margin) for my buffers?
body: <p>In MacVim the text that I'm editing in all buffers is jammed up hard against the left hand side of the buffer. I find this quite visually jarring, especially if I'm looking at a vertical split.</p>
  
  <p>It looks like there is only one pixel between my text and the window border.</p>
  
  <p>Is there a setting that will allow me to add, say, a character width as a gutter or margin?</p>