DataFrame.hist does not accept figsize kwarg

[fonnesbeck]

Unlike DataFrame.plot the hist method does not recognize the figsize kwarg:

AttributeError: Unknown property figsize

It would be extremely helpful for hist to be easily resizable, as the default layout for a column-wise set of histograms is rarely readable for even a moderate number of columns.

[cpcloud]

@fonnesbeck does the above pr do what u want?

[fonnesbeck]

Works for me. Thanks!