ENH: Add vbench

Closes #936

Still a WIP atm.  This is just the skeleton and I've got a few details to iron out over the next couple of days.

Do we know what kind of machine this will be running on?  I can test in a windows VM if need be, I just need to setup a python environment.

I'm keeping some docs too.

Here's an example of the output!

![ols](https://f.cloud.github.com/assets/1312546/1076279/baddb54c-14df-11e3-8cde-acb425362bc1.png)