show() methods

[johnmyleswhite]

As we add more complex distributions like the multivariate normal it might be helpful to make formal show() methods for different distributions. I would propose the following defaults:

• Show states the type of the distribution
• Show shows the parameters of the distribution line-by-line
• Show provides the mean and variance of the distribution as the last two lines

The last pieces are arguably superfluous, but I think they would help when working with things like the Beta and Gamma distributions for which the mean and variance are never obvious to me without doing an explicit calculation.

[johnmyleswhite]

I added a draft of this in 11632df

It should give you a flavor of how this kind of show method would feel.

[johnmyleswhite]

Since no one's objected to this, I'm going to close this issue.