Version 1.7.5 of the BAS package adds an internal function to count the number of models
that satisfy "hereditary" constraints. This is used in the force.heredity option
in bas.lm to reduce the number of models considered in the sampling process and should
reduce the memory requirements and speed up the sampling process. This currently works only
for factors included in the model formula, but not with factors always included in the model
orwith other hereditaty constraints such as with polynomials. (theforce.heredity option
does work with these other constraints). This is a first step in reducing the number of models
allocated in the sampling process. Future updates will include other hereditary constraints.
