Idea: Improving Bootstrap
I think we could improve bootstrap functionality because what we have [now](https://github.com/pydata/pandas/blob/master/pandas/tools/plotting.py#L577) is limited in terms of customization and functionality. Right now we only calculate mean, median and mid ranges and basically plot them all in the same figure.

 It would be nice to be able to pass in specific stat functions, have customizable parameters such as number of samples and sample sizes and different calculation methods, such as this [library](https://github.com/cgevans/scikits-bootstrap/blob/master/scikits/bootstrap/bootstrap.py#L20).
