pydata/pandas — pull request #8297 by TomAugspurger (2014-09-17 18:59:06+00:00)
Title: API: accept -1 for layout in plot functions

Closes https://github.com/pydata/pandas/issues/8071#issuecomment-55906171

![ex](https://cloud.githubusercontent.com/assets/1312546/4309486/b0f963f4-3e9c-11e4-965f-f0ed78c1412b.png)