TODO

rank ordering and inference with ideal output (11/14/2006; pauljtran@gmail.com)

vignette and Sweave etc in doc directory (07/10/2006)

easy generation of simulated roll call data (07/10/2006); but see wnominate::generateTestData

Plot discrimination parameters against closeness of votes, lack of fit
diagnostic (07/10/2006)

Concatenating rollcall objects  (06/23/2006)

Check for redundancies in roll calls (06/23/2006)

Create a boxplot method for class ideal, ideal points by party (06/23/2006)

Create a plot method for class rollcall (principal components) (06/23/2006)

Other fitting options in ideal (principal components, NOMINATE)

User-specified colors in plot.ideal
More control of labels in plot.ideal

Let users append additional MCMC output to an earlier run on the same
data (add need some sanity checks for this)