- Revive the "lmer" and "glmer" classes.  Slots like "family" should
  be in "glmer" only.  Many methods for "lmer" can be simplified as,
  for example, they will always use the scale factor.

- Add a "pedigree" class and methods for it.  Allow a pedigree
  argument in lmer.

- change the status vector to an integer vertor.  The steps are
  cumulative so we only keep track of the stage.  Also REML and glmm
  are stored here.

- anova method for lmer objects.  Will entail saving the terms
  attribute.

- Move large data sets into a MEMSS or mlmRev package

- Change Calloc/Free patterns in the calculation of bVar

- Re-write the ccoef methods in C

- Evaluate the likelihood of a fitted GLMM by the Laplacian approximation