TODO

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

easy generation of simulated roll call data (07/10/2006)

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

Post-processing for ex-post identification constraints

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